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Armagh Observatory
Annual Report
Calendar Year 1999
Prepared by the Director
M.E. Bailey

Contents
1 Astronomy in Armagh 1
1.1 Armagh Observatory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Armagh Planetarium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.3 Mission Statement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.4 Research Areas and Facilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.5 Public Understanding of Science . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.6 Highlights 1999 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2 Research 4
2.1 C.J. Butler, Research Astronomer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.1.1 Stellar Astrophysics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.1.2 Solar Variability and Climate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.1.3 Other Activities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.2 J.E. Chambers, Research Astronomer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.2.1 Research Highlights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.2.2 Collaborations and Other Activities . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.3 J.G. Doyle, Research Astronomer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.3.1 Solar Physics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.3.2 Cool Stars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.4 C.S. Jeffery, Research Astronomer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.4.1 Star Deaths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.4.2 Major Research Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.4.3 Other Work and Activities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.5 M.D. Smith, Research Astronomer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.5.1 How do Stars Form? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.5.2 Herbig­Haro Objects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.5.3 Other Work and Activities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.6 M.E. Bailey, Director . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.6.1 Near­Earth Objects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.6.2 Leonid Meteor Research . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.6.3 Scientific Administration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.7 M. de Groot, Consultant Research Associate . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.7.1 Correlation between Spectroscopy and Photometry in P Cygni . . . . . . . . . . . 13
2.7.2 Investigation of the S Dor Phenomenon in Luminous Blue Variables . . . . . . . . 13
2.7.3 Other Activities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.8 W.M. Napier, Senior Research Fellow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.8.1 Zodiacal Cloud . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.8.2 Quasar Redshifts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
3 Visitors and Seminars 14
4 Public Understanding of Science 15
4.1 Total Solar Eclipse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
4.2 Press, Radio and Television . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
4.3 Astropark . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4.4 History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4.4.1 Meteorological Record . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4.4.2 Heritage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
5 Staff 17
5.1 Staff Movements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
6 Research Activity and Funding Trends 17
A Armagh Observatory Staff 1999 19
i

B Board of Governors and Management Committee 1999 20
B.1 Board of Governors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
B.2 Management Committee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
C Refereed Journal Publications 1999 21
D Armagh Observatory Seminars 1999 23
E Talks by Armagh Observatory Staff 1999 24
F Identified Media Mentions 1999 26
ii

1 Astronomy in Armagh
1.1 Armagh Observatory
The Armagh Observatory, founded in 1790 by Archbishop Richard Robinson, is a modern astronomical
research institute with a rich heritage. The Observatory is set in 14 acres of landscaped gardens and
parkland close to the centre of the City of Armagh, and is the oldest astronomical observatory in the UK
still functioning as an independent research establishment on its original site.
The Observatory is about the size of a small university department, but with the greater responsibil­
ities and the higher public profile of an independent institution. Following the establishment of devolved
structures within Northern Ireland during 1999, responsibility for the Observatory was transferred from
the Department of Education Northern Ireland (DENI) to the new Department of Culture, Arts &
Leisure (DCAL). In recent years the Observatory has received an annual budget from the DENI in the
range $400k--$500k together with external income, mostly originating from the UK Particle Physics and
Astronomy Research Council (PPARC), amounting to roughly 50% of this, i.e. $200k--$300k per year.
There are currently (end December 1999) 25 research staff, including 8 senior astronomers and re­
search associates, 5 postdoctoral research assistants, and 12 research students. The majority of the
students are registered for postgraduate degrees (MPhil or PhD) at the Queen's University of Belfast
(QUB). Discussions with QUB during 1999 have led to recognition of the Observatory as an approved
institution for supervision and examination at postgraduate level. The research, academic and public
outreach activities of the Observatory are supported by 7 staff, 4 of whom have responsibilities for core
activities such as library, computers, meteorology readings, buildings and grounds, while 3 others provide
administrative, secretarial, financial and general personnel support. The Administrator occupies a joint
position with the Armagh Planetarium. The current staff position of the Armagh Observatory is given
in Appendix A.
1.2 Armagh Planetarium
The Armagh Planetarium was founded in 1968 by Dr E.M. Lindsay, seventh director of the Armagh
Observatory, as a public outreach facility of the Observatory. The Planetarium educates and informs
visitors of all age groups, promotes the public understanding of science, and is one of the leading visitor
attractions in Northern Ireland and Armagh City and District. The Armagh Observatory primarily
carries out astronomical research, and is an internationally recognised centre of research excellence with
an organization and infrastructure geared to achieve that aim.
Senior management responsibility for the Armagh Observatory and the Armagh Planetarium rests
with a joint Board of Governors and a joint Management Committee, the two organizations sharing the
position of a joint Administrator. The membership of the Armagh Observatory and Planetarium Board
of Governors and Management Committee is given in Appendix B.
1.3 Mission Statement
The joint mission statement of the Armagh Observatory and Planetarium is:
To advance the knowledge and understanding of astronomy and related sciences through the
execution, promotion and dissemination of astronomical research nationally and internation­
ally in order to enrich the intellectual, economic, social and cultural life of the community.
1.4 Research Areas and Facilities
The principal research interests of Observatory staff now include
1. Stellar Astrophysics: including star formation, astrophysical jets, the Sun, cool stars, hot stars,
helium stars, star­spots, flares, circumstellar dust;
2. Solar System Astronomy: including celestial mechanics, planet formation, dynamical evolution of
comets and asteroids, interplanetary dust; and
3. Solar System -- Terrestrial Relationships: including solar variability, climate, accretion of interplan­
etary dust and comet/asteroid impacts.
1

These areas of astronomy, namely: Stellar Astrophysics, the Sun, Solar System Astronomy, and the
Earth's Climate, encompass those areas of astronomy which promise to have maximum impact on our
lives over the next decade or two. In the short­term, the value of astronomy in Armagh can also be
measured by the amount of external income (and number of people) attracted into Northern Ireland
by Armagh Observatory staff, and by the positive publicity generated for Northern Ireland on both the
national and international scenes.
In addition to these principal research areas, staff at the Observatory have also carried out research
on (i) the structure of meteor streams; (ii) the puzzling apparent quantization discovered in extragalactic
redshifts; and (iii) climate change at Armagh during the past two hundred years. The Armagh climate
series, which is one of the longest in the world from a single site, has special value in being (a) virtually
continuous since its inception in 1795, and (b) only slightly affected by surrounding urban development.
The 20--30 astronomers of graduate or postdoctoral status who work at the Armagh Observatory
come from many countries, and are actively involved in many research collaborations and international
partnerships, including scientific links with almost 60 groups from more than a dozen countries around
the world. These are listed in Appendix E. Full details about the Armagh Observatory and its current
research programmes are available from the Observatory web­site: http://www.arm.ac.uk/.
The astronomical research facilities at Armagh Observatory, including those for computing and data
reduction, are mostly excellent, and include a local Starlink node funded in part by the Particle Physics
and Astronomy Research Council (PPARC) and partly by the DENI/DCAL, and (from March 2000)
an Origin 2000 supercomputer. Armagh Observatory staff receive regular awards of telescope time and
research grants from the PPARC and other organizations, and are eligible to apply for grants from the
Natural Environment Research Council (NERC) and other grant awarding organizations.
1.5 Public Understanding of Science
In addition to its principal function as an astronomical research institute, the Armagh Observatory has
a responsibility to disseminate widely the results of its astronomical research. The Observatory plays a
major role in the promotion of astronomy and the public understanding of science, both locally (i.e. within
Armagh City and District and Northern Ireland) and abroad. The Observatory's public outreach focuses
primarily on e­visitors to its web­site (http://www.arm.ac.uk), on mass­media interest in astronomy (via
the national and local press, radio and television), and on the development, preservation and restoration
of the Observatory's two­hundred year astronomical heritage, comprising written records and archives,
scientific artefacts, historic buildings and telescope domes, scientific instruments, telescopes, and grounds.
It is estimated that tens of millions of people were reached last year through the various media contacts,
with a further 100,000 e­visitors being recorded from over 100 different countries.
The more than 200 years of continuous astronomical activity in Armagh encompass essentially the
whole of modern astronomy. This provides the research scientists who work in Armagh with a unique
opportunity to explain the motivation for the development of their subject over this period, specifically
in Armagh, and the context in which their present research is carried out. The grounds in which the
Observatory is located are attractively laid out, and include a scale model of the universe known as
the Armagh Astropark. The Astropark is now being developed as part of the Observatory's public
understanding of science programme.
1.6 Highlights 1999
ffl Explaining the 1998 Leonid Fireball Outburst: David Asher, Vacheslav Emel'yanenko (vis­
iting the Observatory from Chelyabinsk, Russia) and Mark Bailey explained the unexpected Leonid
fireball outburst in the early hours of 17 November, which occurred more than half a day earlier
than the predicted meteor shower on the night of 17/18 November 1998. The explanation for the
1998 Leonid fireball outburst attracted much scientific and public interest, and gave rise to media
reports in many newspapers and magazines around the world, including The Times, Der Neue
Zuercher Zeitung (Zurich), Scientific Computing World, Science News, The Boston Globe, and The
Dallas Morning News.
ffl Predicting the 1999 Leonid Storm: David Asher also explained previous Leonid meteor storms
(notably the great storms of 1833 and 1966), and together with Rob McNaught (Australian National
University, Siding Spring Observatory) made accurate predictions for the times of the `normal' storm
trails of the Leonids. The prediction for the 1999 storm (for November 18 02 h 08 m ) turned out to
be `spot­on', and made headlines around the world. The success of the Asher/McNaught approach
in predicting the time of the meteor storm was hailed by the editor of the International Meteor
2

Organization 1 as equal in importance to the basic understanding of how meteors work, following
the famous 1833 storm. David Asher has also computed the circumstances of the Leonid meteor
showers for 2000, 2001, 2002 and 2006 (see http://www.arm.ac.uk/leonid). The 2000 event involves
the Earth's first passage through the 4­revolution trail of meteoroids ejected from the comet in
1866. Observations of these meteoroids will be crucial for predicting the precise meteoroid flux in
2001 and 2002.
ffl Stellar Evolution Following Stellar Merger: Simon Jeffery, in collaboration with Hideyuki
Saio (University of Tohoku, Japan) has developed a new evolutionary model for the pulsating
helium star V652 Herculis. In this model, two helium white dwarfs in a binary system coalesce.
The increased mass of the new star allows nuclear burning to begin and the star becomes a giant.
Its subsequent evolution provides models which match the observed properties of V652Her almost
perfectly.
ffl Pulsation Mass for Second Helium Star: In two studies of a pulsating helium star LSS 3184,
which has properties very similar to V652 Her, Simon Jeffery, Vincent Woolf and collaborators
at the South African Astronomical Observatory have measured the radius and mass. Somewhat
surprisingly, the results were somewhat smaller than expected. Since LSS 3184 has a carbon­rich
surface, while V652Her has a nitrogen­rich surface, this raises new questions about their possible
evolutionary origin.
ffl Rare Earth: John Chambers, in collaboration with George Wetherill (Carnegie Institution, Wash­
ington), has made computer simulations of the origin and formation of the Earth and inner planets,
yielding Earth­like planets moving on almost circular orbits, allowing them to have potentially sta­
ble climates. The fraction of planets with orbits lying entirely in the habitable or `Goldilocks zone'
around other stars (neither too hot nor too cold) is very small, suggesting that living organisms as
complex as those found on Earth might be of exceptionally rare occurrence in the Universe.
ffl Solar Influence on Climate: A new correlation between the global low cloud factor and cosmic­
ray flux, found by Enric Pall'e Bag'o and John Butler, suggests that a substantial fraction of the
global warming since the late­nineteenth century can be explained by a combination of the direct
(solar luminosity change) and indirect (cosmic­ray induced change in cloudiness) effects of solar
activity.
ffl Detection of Nano­Flares: Gerry Doyle and Luca Teriaca have interpreted red­shifted spectral
lines in the solar atmosphere (temperatures 20,000--200,000K), and blue­shifted features at higher
temperatures, in terms of nano­flares in a magnetic loop around the O vi formation temperature.
ffl Honorary Professorship: Gerry Doyle was awarded an Honorary Professorship from QUB, start­
ing 1999 June 1.
ffl Minor Planet for DENI: The asteroid (9140) Deni was formally announced by the International
Astronomical Union Minor Planet Center on 1999 April 2 (ref. MPC 34351). The citation reads:
``(9140) Deni = 4195 T­3.
Discovered 1977 October 16 by C.J. van Houten and I. van Houten­Groeneveld on Palomar
Schmidt plates taken by T. Gehrels. Named after the Department of Education for
Northern Ireland for its support of the Armagh Observatory, where Ernst ¨
Opik carried
out seminal work on the collisional evolution and dynamics of small bodies. The DENI
has promoted lifelong learning and research across many disciplines, encompassing higher
education, schools, museums, recreation and culture. It has sought for many years to
advance knowledge and understanding of the natural world, and to provide the means
by which as many people as possible may appreciate and continue to develop Northern
Ireland's rich cultural heritage, its diversity and contributions to the scientific, intellectual
and social life of the community.''
ffl Centre Stage in Dublin: A fictional account of the life of Robert Hogg, assistant astronomer at
Armagh Observatory in the 1790s and early 1800s, provided the inspiration for Darragh Carville's
Gothic Sci­Fi thriller ``Observatory'', which was shown at the The Peacock Theatre Dublin, during
April 1999.
1 Rendtel, J., 2000, Editorial, WGN, The Journal of the International Meteor Organization, 28, 1.
3

ffl Media Coverage: The Observatory is one of the principal points of contact for astronomy in both
Northern Ireland and the Republic of Ireland, receiving many public enquiries and citations in the
national and international press, and on radio and television. During 1999, the Observatory was
noted in one or another such medium at least 233 times. These identified media mentions, which
are a subset of the whole, are listed in Appendix F.
ffl External Grant Income: Total external grant income during the financial year 1999/2000 was
$293k, an increase on the previous year and a significant fraction (65%) of the total DCAL recurrent
grant­in­aid ($452k). Total external income (excluding $125k in kind through the Joint Research
Equipment Initiative) was $305k.
2 Research
A subset of the total research output of Observatory staff, namely the list of 32 refereed journal publica­
tions during 1999, is given in Appendix C. A second subset, namely the list of more than 65 public and
professional talks delivered by Observatory staff during 1999, is given in Appendix E.
These examples illustrate two of the many routes by which the research results of Observatory staff
are communicated to a wider public: through talks or popular articles in the local, national or scientific
media; at conferences, seminars and workshops; in books; in refereed scientific publications and journals
(some of which nowadays are entirely in electronic form, e.g. The Journal of Astronomical Data); in
conference proceedings; and in a variety of non­refereed publications. It is notable that the proceedings
of the Brendan Byrne Memorial Meeting 2 were published within 6 months of the meeting taking place.
These forms of research activity all help to raise the profile of astronomy on the national and inter­
national scenes and highlight in particular the role of astronomy in Armagh.
A second indication of the quality and volume of the Observatory's research output is the amount
of external research income, raised mostly through a process of competitive grant application and peer
review. This is a fluctuating quantity which has fallen in recent years, due in part due to a temporary
shortage of funding for external PPARC research grants. The total external grant income for 1999/2000,
namely ¸$293k, therefore represents an exceptionally good performance, being a substantial fraction
(65%) of the total DENI/DCAL recurrent grant­in­aid for the financial year in question.
External income generation and the overall level of research activity are areas where economies of
scale work extremely well. In view of the Observatory's relatively small size, further improvements would
be possible given appropriate investment in additional research staff.
The remainder of this section summarises, under the headings of the Observatory's senior research
staff and associates, some of the principal research results obtained in 1999 by these staff and their
colleagues.
2.1 C.J. Butler, Research Astronomer
2.1.1 Stellar Astrophysics
Observations and Modelling of Stellar Flares A new PhD student, David Garc'ia Alvarez, be­
gan work with Dr John Butler and Professor Gerry Doyle in October 1999 to continue the analysis
and modelling of stellar flares started by Eric Houdebine and John Butler in the late 1980s and early
1990s, subsequently continued by Darko Jevremovi'c from 1995--1999. Dr Jevremovi'c completed his thesis
(`Hydrogen Balmer Lines in Stellar Flares') and was awarded his degree in 1999.
In his thesis work, Darko Jevremovi'c developed a new tool for analysing the Balmer decrements which
made it possible to estimate the electron density and electron temperature of the flare plasma and the
temperature of the underlying background source. Applied to data of flares on Gliese 866 he was able
to estimate the area of hydrogen emitting flare regions as 1--13% of the stellar surface. The physics of
the flare process was taken back a further stage towards its initial cause by the development of a new
gas­dynamic radiative transfer code with heating by energetic electron beams. This code satisfactorily
predicted the behaviour of the Hfl line during a flare observed on AD Leo with the William Herschel
Telescope (WHT) in 1998.
2 Butler, C.J. & Doyle, J.G., 1999, Solar and Stellar Activity: Similarities and Differences, Astron. Soc. Pacific Conf.
Ser., 158.
4

Angular Momentum of Late­Type Cluster Members A paper with Dr Armin Theissen, giving
full details of the astrometric and photometric observations of the open cluster Stock 2, has been accepted
for publication. Proposals for follow­up medium­resolution and high­resolution spectroscopic observations
of probable members of this cluster did not receive the requisite allocation of telescope time, and as a
result it was decided to adopt a different and less observationally demanding approach to our goal of
establishing the rotational velocities of cluster members. This involved photometric monitoring using a
wide­field CCD camera on a medium­sized telescope. Seven nights were awarded on the 1m Ritchey­
Chr'etien Telescope at Siding Spring by the Mount Stromlo and Siding Spring Observatory in February
1999 and again in January 2000. In the first run, mediocre weather conditions prevented successful
photometric tranfers, but did allow some variability studies to be made. During the second run, in
January 2000, two photometric nights allowed photometric transfers to be completed. The data are in
the process of reduction and analysis.
COROT Satellite The French satellite programme COROT, which will be dedicated to micromagni­
tude photometric observations of main­sequence stars, has now received a firm commitment for launch.
The project has two main objectives: (1) to determine the internal structure of main­sequence stars using
asteroseismology techniques; and (2) to search for Earth­like planets around main­sequence stars from
optical occultations.
The selection of the target list using high­resolution spectroscopic data of around 1000 candidate
stars is a major observational programme which requires international collaboration. As partners in the
project, Armagh Observatory has been asked to contribute to the selection process in exchange for priority
access to the data which will eventually flow from the satellite. A one­week run on the South African
Astronomical Observatory (SAAO) 1.9 m telescope using the `Giraffe' Echelle Spectrograph was awarded
to this programme. About 80 high­resolution spectra were obtained, which have now been reduced and
classified by Claude Catala. A further application for time on the WHT has been made. In addition
to the selection of COROT targets, this project will result in a substantial databank of high­resolution
spectra which will be made available for stellar atmosphere studies. Eventually, when the satellite is
operational, Armagh Observatory will gain priority access to a vast and highly original databank of
unparalled photometric accuracy on a wide variety of stars.
2.1.2 Solar Variability and Climate
It is now widely accepted that solar activity plays some role in climate change, but the relative strength
of its influence compared to the enhanced greenhouse effect is still a subject of dispute. The solar activity
effect can be divided into two parts: (1) the direct effect of a solar luminosity change associated with
solar activity, which many agree can explain roughly 10--20% of the current global warming; and (2) an
indirect effect, that is difficult to quantify, but which depends on the influence of solar activity on other
less easily identifiable physical processes. One such possible process is the influence of changes in solar
activity on cosmic­rays and their effect on the Earth's cloud factor.
An anlaysis of data from the International Satellite Cloud Cover Project (ISCCP), by Enric Pall'e
Bag'o and John Butler has shown that previously identified correlations between the total cloud cover
over oceans and cosmic­ray flux for the period 1984--1991, do not continue during the period 1991--1994.
However, when the data are separated into low, medium and high clouds, a clear correlation is evident
between cosmic­ray flux and low clouds over the whole period covered by the ISCCP data from 1984--1994.
Assuming there is no feedback mechanism or other long­term changes, it is then possible to compute the
enhanced warming by low clouds and their influence on the Earth's albedo. Preliminary results suggest
that much of the global warming since the late nineteenth century can be explained by a combination of
the direct and indirect (cosmic­ray induced) effects of solar activity.
2.1.3 Other Activities
John Butler wrote short biographies of several former Armagh Observatory staff (E.M. Lindsay, J.L.E.
Dreyer and E.J. ¨
Opik) for the book People and Places in Irish Science, edited by Charles Mollan (Royal
Irish Academy, Dublin), and served on several external committees including the Court of the University
of Ulster and the Birr Scientific Heritage Trust. He has also been the principal point of contact between
Armagh Observatory and Trinity College Dublin (TCD), for the programme in which, each autumn,
Armagh Observatory staff develop and supervise undergraduate astronomy projects for final­year TCD
students.
5

2.2 J.E. Chambers, Research Astronomer
2.2.1 Research Highlights
John Chambers has refined and expanded an alternative scenario for the formation of the asteroid belt
in collaboration with George Wetherill, Carnegie Institution of Washington, USA. Using numerical sim­
ulations on computers, they have shown how planets may have formed in the asteroid belt. However the
orbits of these planets were made unstable by gravitational perturbations by the giant planets Jupiter
and Saturn. As a result, the planets in the asteroid belt were all lost, falling into the Sun or being thrown
into interstellar space, leaving no planets in the asteroid belt today.
Building on this work, John Chambers and collaborators at Nice Observatory, France, have shown
that most small asteroids would also have been lost, leaving only the ones we see today. They have
also explained why many of the remaining asteroids have highly eccentric and inclined orbits, unlike the
planets in the Solar System.
This same collaboration has shed light on an old mystery: why the Earth has water and organic
material on its surface. This is a long­standing problem since theories for the origin of the Solar System
predict that planetary building blocks (``planetesimals'') that formed at Earth's distance from the Sun
should be very dry. For a long time it was thought that comets collided with the young Earth, bringing
the water and organic material needed for life to form. However recent work has shown this idea is
untenable. The Nice workers and John Chambers have shown that protoplanets forming in the asteroid
belt can supply this material to Earth instead. In collaboration with workers at NASA Ames, John
Chambers is extending this theory to extrasolar planetary systems.
John Chambers has made new detailed computer simulations of the origin and formation of Earth and
the inner planets. These have overcome many shortcomings of earlier simulations, and produce systems
of planets that resemble those in the inner Solar System in many respects. However some differences
remain, suggesting that our planetary system may be special in some way. Dr Chambers is now examining
whether this is related to events that occurred in the asteroid belt and outer Solar System, with the aim
of developing a single coherent model for the formation of our planetary system.
``Mercury'', the computer package for calculating orbital evolution developed by John Chambers, has
now been made publicly available on the Armagh computer FTP site. Collaborations with Marc Murison
at the US Naval Observatory and others should further improve this package in the near future.
2.2.2 Collaborations and Other Activities
During the year, John Chambers undertook scientific collaborations with: J.J. Lissauer and E. Rivera
at the NASA/Ames Research Center, on the formation of the inner planets and the Moon; P.N. Sleep
and B. Jones at the Open University, on the stability of terrestrial planets in extra­solar planetary
systems; A. Morbidelli and J.­M. Petit at the Observatoire de Nice, on the origin and early evolution of
the asteroid belt; M. Kress and R. Bell at NASA/Ames, on delivery of volatile materials to Earth­like
planets in extra­solar planetary systems; E. Thommes and M. Duncan, Queen's University Canada, on
the formation of the outer planets and the asteroid belt; M.A. Murison at the US Naval Observatory,
on developing better computer algorithms for solving the N­body problem; G.W. Wetherill at Carnegie
Institution of Washington, on planet formation and the formation and evolution of the asteroid belt; and
G. Stewart, University of Colorado, on N­body integrators.
John Chambers also served as external examiner for a PhD student at Oxford University, refereed
a number of papers and grant applications for PPARC, NASA and the Austrian Science Council, and
presented a number of papers at colloquia and scientific conferences.
2.3 J.G. Doyle, Research Astronomer
The major research effort in 1999 was again directed towards Solar Physics and in particular towards
SOHO activities, although some effort was directed towards the cool star area.
2.3.1 Solar Physics
This work can be broadly divided into four areas, each of which is briefly discussed below. In addition
to Gerry Doyle, those involved include Luca Teriaca, Il'ia Roussev, Elena P'erez, and Dipankar Banerjee.
Coronal Holes SUMER/SOHO and CDS/SOHO data were obtained for spectral lines from two ions
formed at high temperatures, Si viii and Si ix. Lines from these ions provide both an estimate of the
local electron density and micro­turbulent plasma velocity. From the combined dataset we find a radial
6

dependence of the electron density, varying in the range 1--2R fi as r \Gamma8 , from 2--4R fi as r \Gamma4 and then
as r \Gamma2 . By 8R fi , the electron density has fallen to ¸ 4 \Theta 10 3 cm \Gamma3 , from 1:5 \Theta 10 8 cm \Gamma3 at 1:0R fi .
Combining the Si viii half­width at 1/e of the peak intensity with the UVCS/SOHO O vi half­width, we
find a small increase of the half­width from 1.0--1.2R fi , then a plateau until 1.5R fi , thereafter a sharp
increase until 2R fi , and finally a more gradual increase reaching 550km s \Gamma1 at 3:5R fi . Our data suggest
that the magnetohydrodynamic (MHD) waves responsible for the excess line broadening tend to become
non­linear as they reach 1.2R fi .
Chromospheric Oscillations We examine spectral time­series of two lower­chromospheric lines ob­
served with SUMER/SOHO (N i and C ii). Intensity power spectra of C ii are affected at higher frequen­
cies by streams of emitting structures. Using contrast­enhanced time slices we show that (1) there exists a
grain­like pattern which is found in both network and inter­network regions; (2) streams of supersonically
moving structures probably outline a wave interference pattern; and (3) the sizes of structures observed
in N i are smaller than when observed in C ii. At various points our findings disagree with earlier results.
Explosive Events Two examples of explosive events observed with SUMER/SOHO in transition region
spectral lines are reported here; one detected in C iv 1548 š A, in a region within the northern polar coronal
hole, and the other in O vi 1032 š A, in an active region. The event measured in C iv lasted approximately
3 minutes, with velocities reaching around 150km s \Gamma1 in the blue wing and 100km s \Gamma1 in the red wing.
The active region events were more energetic and in total lasted ¸6m. More precisely, we have at least
two consecutive events occurring in a short time interval (¸12 m) separated by ¸3 arc sec. The explosive
events seen in O vi showed a very complex structure of subsonic and supersonic velocity flows, both red­
shifted and blue­shifted. The apparent maximum velocity reached in the blue wing was approximately
250km s \Gamma1 and 215km s \Gamma1 in the red wing.
There appears to be evidence of super­granular cells, with the increase in electron density occurring
along the network boundaries. At some locations, periodicities of between 8 and 16 minutes are visible
in the electron density variations.
In order to learn more about these explosive events, simulations were made assuming semi­circular
magnetic flux tubes in a hydrodynamic code. The temporal evolution of the thermodynamic state of the
loop was converted into C iv 1548 š A line profiles. Departures from ionization equilibrium were assessed
for the first time under conditions such as those encountered in explosive events. Work is well advanced
on developing a 2­D MHD code.
Doppler Line Shifts The ultraviolet spectral lines formed at transition region temperatures in the
solar atmosphere, show a prevailing line­shift. The velocities increase from a red­shift of ¸0km s \Gamma1 at
¸20000K, to 10km s \Gamma1 at 1:9 \Theta 10 5 K for the quiet Sun, and to ¸15km s \Gamma1 at 1:0 \Theta 10 5 K for the active
region. At higher temperature an opposite behaviour is observed. In the quiet Sun a blue­shift of ¸2km
s \Gamma1 is observed at the Ne viii formation temperature (6 \Theta 10 5 K), while in the active region a blue­shifted
value around ¸8km s \Gamma1 is observed for the same spectral line. With these data we explore the idea
that the occurrence of nano­flares in the magnetic loop around the O vi formation temperature could
explain the observed red­shift of mid­to­low transition region lines as well as the blue­shift observed in
low coronal lines. Performing an integration over the entire period of simulations, a red­shift of ¸6km
s \Gamma1 is found in C iv, while a blue­shift of ¸2km s \Gamma1 and ¸10km s \Gamma1 were derived for O vi and Ne viii,
respectively, in reasonable agreement with observations.
2.3.2 Cool Stars
These results are divided into three principal areas, as discussed below, and include work by Ferhat
Ozeren and Darko Jevremovi'c.
Algol­Type Binaries We present radio interferometric observations of the Algol­type binary system
V505 Sagitarii made with the ATNF Compact Array at 6 cm and 3.6 cm over one orbital cycle (1.18
days). The radio flux level shows a clear modulation with evidence of eclipses of the emission region at
both conjunctions of the binary, which may indicate the existence of an intra­binary region of activity.
This has important consequences for the details of coronal formation and field interaction in active close
binary stars.
7

CVn­Type Binaries We investigate the extent to which the Wilson­Bappu relationship holds for
chromospherically active binaries using the Mg ii h and k lines of 41 RS CVn stars observed with the
International Ultraviolet Explorer satellite (IUE). The resulting fits are different from the relationships
obtained for single, less active stars. Within a particular luminosity class the relationship is good, but it
tends to break down when we incorporate objects ranging in luminosity from Class i to v. From model
calculations there is very little dependence of the Mg ii line­width on effective temperature. The line­width
does however depend on the column mass at the transition region boundary showing increased line­width
at lower column mass. There is also a dependence on the column mass adopted for the temperature
minimum, although the major and dominant parameter is the surface gravity, g, scaling as g \Gamma1=4 . Within
a given luminosity class more active objects will show larger line­widths, reflecting a higher column mass
deeper in the atmosphere, e.g. at the temperature minimum level.
Carbon and Oxygen­Rich Systems We have developed a new method to determine the physical
properties and the local circumstances of dust shells surrounding Carbon and Oxygen­rich stars for a
given pulsation phase. The observed mid­infrared dust emission feature(s), in conjunction with both
near­infrared and far­infrared photometry, are modelled from radiative transport calculations through
the dust shell using a grid of detailed synthetic model input spectra.
2.4 C.S. Jeffery, Research Astronomer
2.4.1 Star Deaths
Stellar corpses are the burnt­out remains of stars which have exhausted their reserves of energy and have
ceased to shine. All that may be seen is the glowing cinder as the star gently cools, or the signature of
energized material trapped in their enormous gravitational and magnetic fields. Well known examples
include black holes, white dwarfs and neutron stars. They are amongst the most exotic objects in the
Galaxy --- our mission is to discover how normal and benign stars like the Sun reach such macabre ends.
In pursuing it, we also study the origins of elements essential to human life, the physics of matter under
extreme conditions and processes that affect the evolution of entire galaxies.
The conventional paradigm has a Sun­like star swell up to become a red giant as it finishes converting
hydrogen to helium. Pausing to convert helium to carbon and oxygen, the expansion then continues until
the star sheds its outer layers as a planetary nebula and shrinks to become a white dwarf. However many
stars do not fit comfortably into this picture, particularly those which have become so mixed up that
even their outer layers have no hydrogen left. These are the helium stars and the hot subdwarfs.
The problem demands that we study stars that are in transition between hydrogen burning and death.
Such phases frequently do not last long --- a few thousand years or less --- and hence such stars are rare.
We must measure their properties in as much detail as possible. For instance, we would like to know
their mass, radius and luminosity at the very least. The chemical composition of their surface layers can
provide clues to past evolution, particularly if material processed by nuclear reactions in the interior has
been exposed at the stellar surface. It is also important to know if the star is or was one of a pair --- a
binary star --- because such stars can exchange mass with their companion as they evolve.
The Armagh approach combines high­quality observations with the best possible theoretical models,
covering every aspect of stellar structure from the deep interior to the outermost layers of the atmosphere.
Our theoretical work involves making hypotheses about the origin of given stars. These define boundary
conditions for solving the time­dependent equations of stellar structure. Such solutions show long­term
evolution in response to changes in chemical composition at different points within the star, and short­
term changes (pulsations) in response to instabilities in the energy flow from the star. Our theoretical
work also involves the construction of detailed models of the outermost layers of the star and the spectrum
of radiation they emit.
2.4.2 Major Research Results
In 1999, Simon Jeffery and Hideyuki Saio (Japan) completed a new evolutionary model for the origin
of one particular helium star, V652 Herculis, which involves two helium white dwarfs in a binary. The
capture of one white dwarf by the other provides a new source of nuclear fuel so that the star is able to
expand briefly to become a giant. Unlike most stars which burn from the inside out, nuclear reactions
are ignited on the outside of the original white dwarf and then start to burn inwards. As it does so,
the star's properties change so that at one point they match the current properties of V652 Her almost
perfectly.
8

The analysis of stellar spectra can be a time­consuming and subjective task which involves the fitting
of models with many free parameters to observations of varying quality. An important development in
1999 was the initiation of a project to build software for the automatic, efficient and objective analysis
of stellar spectra. By the middle of the year, we were able to measure the effective temperatures,
apparent diameters and the interstellar extinctions for both single and binary stars from their observed
flux distributions. This enabled observational studies of evolution and pulsation in helium stars and
of the physical dimensions of hot subdwarfs with cool companions to be rapidly progressed. The new
software will be extended to measure other properties of stellar atmospheres during 2000.
The third major achievement of 1999 were two detailed studies of the pulsating star LSS 3184 --- a
helium star very similar to V652 Her. The first was based on observations obtained by Simon Jeffery at
the South African Astronomical Observatory in 1995. Although normally impossible to measure for a
single non­variable star, radius and distance can be measured for a pulsating star by observing its colours
and surface motion through a pulsation cycle. Together with a previous measurement of surface gravity,
these observations pointed to a mass too small to be realistic. Dr Vincent Woolf joined the Armagh team
as a postdoctoral research assistant in 1999 July, and commenced work on very high­quality observations
obtained by Simon Jeffery with the Anglo­Australian and the Hubble Space Telescopes in 1996/1997.
These set new and tight constraints on the radius of LSS 3184 and partially resolved the mass problem.
2.4.3 Other Work and Activities
In 1900, FG Sagittae was an uknown faint blue star. Since then it expanded to become a cool giant
helium star. With Sch¨onberner (Potsdam), Simon Jeffery commenced a project to measure changes in its
surface composition during the expansion using archival spectra. This complements an ongoing project
with Don Pollacco (QUB) to study the chemical evolution of Sakurai's object --- an even more rapidly
expanding star which suddenly appeared in 1996.
Short­period non­radial pulsations in hot subdwarfs were discovered during the early 1990's using
photometric techniques. Simon Jeffery and Don Pollacco made high­speed measurements of their surface
motions; 2600 spectra were have been analyzed and exciting new results will be announced in 2000.
Because they are rare, the identification of new helium stars and helium star classes is an ongoing
task of stellar pathology. New surveys and instruments provide thousands of new spectra which require
classification and analysis. The definition of a spectral classification system for hot subdwarfs (with John
Drilling, Louisiana) is nearly complete. Brian Mahon (Trinity College Dublin) and Simon Jeffery applied
neural network software to the automatic classification of subdwarf spectra.
Regina Aznar Cuadrado and Simon Jeffery also made observations of binary subdwarf B stars and
extreme helium stars with the Isaac Newton and Jacobus Kapteyn Telescopes in La Palma. An inconclu­
sive search for periodic variations (pulsations) in two hot helium stars was presented at IAU Symposium
176 in Budapest. Regina Aznar Cuadrado is using spectra and photometry of hot subdwarfs to measure
the absolute dimensions of those stars with faint companions.
Pilar Monta~n'es Rodr'iguez studied the effect of projection on the profiles of spectral lines in pulsat­
ing helium stars and presented her results at IAU symposium 176. She commenced hydrodynamical
calculations of the pulsations in luminous helium stars.
Vincent Woolf made spectroscopic observations of post­AGB stars with the Anglo­Australian Tele­
scope, with a view to exploring the surface exposure of elements produced by the nuclear s­process while
the star was a red giant.
Observations made by Simon Jeffery with the International Ultraviolet Explorer of the helium­rich
white dwarf HS2253+8023 containing traces of hydrogen and metals were analysed and shown to be
consistent with a relatively cool (15 000K) white dwarf accreting material from the interstellar medium.
During the year Simon Jeffery also obtained a number of external research grants (including a 3­year
PPARC PDRA grant to support Dr Woolf), and presented colloquia locally and abroad, and a number
of popular talks.
2.5 M.D. Smith, Research Astronomer
2.5.1 How do Stars Form?
A collapse or implosion of a cloud of gas containing molecules and dust may lead to a low­mass star
like our Sun. High­mass stars could form through the accretion of smaller protostars. By studying the
physics of molecular clouds, we hope to learn if and why the collapse occurs.
We have investigated the nature of the molecular clouds by performing computer simulations. These
new simulations account for many, but not all, realistic cloud properties. In three dimensions, with
9

supersonic turbulence and magnetohydrodynamics, we have analysed the fields of shock waves produced.
In work carried out together with Mac Low (New York), Zuev (Colorado), Heitsch (Heidelberg) and
Klessen (Leiden), we have been able to distinguish between decaying turbulence, producing an exponential
spectrum of shock speeds, and driven turbulence, producing a specific power­law spectrum.
A Unification Scheme for protostars was developed and extended in several directions. Clear predic­
tions were made which have proven invaluable in stimulating and motivating new research projects. The
scheme adopts the hypothesis that the mass of cloud gas is redistributed through several components.
The core, envelope, accretion disc, jets and outflow all evolve on the same time­scales, passing through
distinct stages from birth (Class 0 protostar), toddler (Class 1), childhood (Class 2), puberty (Class 3)
to adolescence (Pre­Main Sequence).
The simple rules yield evolutionary tracks on diagrams relating any two of the above components.
In a collaboration with Stanke (Bonn) and Zinnecker (Potsdam), work is now underway to test these
predictions against statistics obtained from wide­field infrared surveys. An extension of the Unification
Scheme to lower mass proto­brown­dwarfs suggests that they too will possess detectable outflows.
2.5.2 Herbig­Haro Objects
The interaction of young stars with their surroundings are accentuated within Herbig­Haro Objects,
where streams and `bullets' of ejected gas impact on the ambient molecular clouds. Infrared observations
penetrate the clouds and reveal the processes occurring deep within. We are progressing with a programme
of infrared observations and interpretations of the outflows. This includes a large­scale imaging study of
bow shocks in the Orion Molecular Clouds (with Ka Chun Yu and Bally et al., Colorado) and spatially­
resolved excitation and kinematic studies of well­known outflows (with Eisl¨offel, Tautenburg, Germany;
and Davis, UKIRT, Hawaii) such as HH 1/2 and HH 46/47.
The question how objects can be accelerated to and maintain high speeds is important not only to
astronomers. Projectiles --- be they torpedoes, rocks, missiles or people --- are slowed down by friction as
they try to penetrate their environments, creating bow waves, sonic booms and turbulent wakes. In our
Galaxy, in regions associated with young stars and star formation, we now realize that there are swarms
of projectiles called Herbig­Haro Objects, named after the two scientists who first researched them. They
appear to move ballistically --- like cannonballs. But what are they doing there, where are the cannons
and why were they fired?
We have now detected many jets of these interstellar bullets amidst narrow streams of gas. The jets
are sometimes found in symmetric pairs, at the centre of which we can often only just see some highly
obscured star­like bodies. These bodies turn out to be protostars: the stars­to­be. The moment a star is
born is signalled by a round of cannon­fire!
The astrophysical jets are spectacular. But why should star birth be accompanied by such violent
events? Recent work has shown that they are essential to the whole star­formation process. A star
cannot easily form in isolation because of angular momentum conservation: it would wind up spinning
so fast that it would be unable to collapse. It appears that the jets and bullets carry away the angular
momentum during the final collapse. Michael Smith and collaborators have searched for, and found, the
first evidence of rotation within the jets.
Observed over several years, the associated interstellar bullets are found to move at hundreds of
kilometres per second. This leaves us with new questions: how can molecules survive such shattering
speeds, and how do the cloud and protostar contrive to transfer angular momentum from the cloud to
the bullets? Michael Smith hopes that finding the answers to these problems will ultimately contribute
to our ability to control energy resources and to fly faster, on top of the direct goal of understanding our
Universe. To this end, he is now undertaking a new programme of supercomputer simulations in which
models for the interstellar bullets can be tested.
2.5.3 Other Work and Activities
In addition to this work on star­forming regions in our own Galaxy, Michael Smith has also begun a
new study of star formation in external galaxies, particularly the very energetic `starburst' galaxies often
associated with distant interacting, or colliding stellar systems. In these objects new stars, especially
massive stars, are being formed at rates, and under extreme conditions, not matched anywhere within
our own Galaxy.
During the year, Michael Smith delivered a number of scientific and popular talks to groups both
locally and abroad, and supervised two QUB undergraduates on summer project work. Towards the end
of the financial year he obtained a research grant through the Joint Research Equipment Initiative to pur­
chase a Silicon Graphics Origin 2000 supercomputer. Under this scheme, the cost of the supercomputer,
10

approximately $250k, is funded partly by the PPARC ($125k), with the balance being provided by the
industrial partner, in this case Silicon Graphics Inc. (SGI). Michael Smith also successfully obtained a
PPARC research grant to support a postdoctoral research assistant for three years to work on the project
`The Origin and Evolution of Protostars: Tracking with Magnetohydrodynamic Numerical Simulations'.
2.6 M.E. Bailey, Director
2.6.1 Near­Earth Objects
During 1999 the Armagh Observatory played a major role in raising public awareness of the comet and
asteroid impact hazard to civilization and in discussions of what, if anything, the UK government should
be encouraged to do about the problem. Following the Adjournment Debate in the House of Commons on
Project Spaceguard, on 1999 March 3, M.E. Bailey was among several astronomers invited to review the
Parliamentary Office of Science and Technology (POST) report #126 (1999 April) `Near Earth Objects',
and was subsequently invited to present a talk on the subject to the Parliamentary Astronomy and Space
Environment Group (PASEG) in the House of Lords (1999 May 10). A copy of this talk, together with
links to related research work and other web­sites, is available at http://star.arm.ac.uk/paseg/.
A subsequent meeting attended by Mark Bailey, Jay Tate (Spaceguard UK), Nigel Holloway (Atomic
Weapons Establishment), Richard Tremayne­Smith and Paul Murdin (British National Space Centre),
together with Sir Crispin Tickell, Lembit ¨
Opik MP and Lord Sainsbury, was held at the Department of
Trade and Industry on 1999 July 8. This meeting reaffirmed the seriousness with which the government
views the comet/asteroid impact hazard, and led to the establishment of a Near­Earth Object `Task
Force' to investigate possible UK options for contributing to the international spaceguard programme.
The Task Force, chaired by Dr Harry Atkinson, will deliver a report on the subject to the government in
2000.
2.6.2 Leonid Meteor Research
Research by David Asher and Mark Bailey, of Armagh Observatory, Vacheslav Emel'yanenko, of South
Ural University, Chelyabinsk, Russia, and Rob McNaught, of the Australian National University, Siding
Spring Observatory, has explained the unexpected, spectacular shower of bright meteors seen in the small
hours of 1998 November 17 and fine structure seen in the incidence of meteors associated with the Leonid
meteor shower of 1999 November 18.
The Leonid meteor display occurs between 15 and 21 November each year, with peak activity on
the night of the 17/18 November. The observed meteors are produced by collisions with the Earth's
atmosphere of small dust particles ejected from the parent comet, Tempel­Tuttle. This object, which is
a ball of dust and ice about 3--5 km across, moves around the Sun in an elliptical orbit with a period of
revolution approximately 33 years. The dynamical features of the orbit are similar to those of Halley's
comet, and comet Tempel­Tuttle is therefore classified as a Halley­type short­period comet. Owing to
the extreme inclination of the cometary orbit (162 degrees), the dust grains collide almost head­on with
the Earth, at a relative velocity of about 71 kilometres per second. At such a speed, a centimetre­size
particle has the same kinetic energy as a speeding truck on a motorway.
A meteor shower is seen every year, but every 33 years or so, owing to the much higher spatial density
of dust grains close to the comet, the intensity of the display is greatly enhanced. In fact, strong meteor
showers, known as `meteor storms', have been seen many times during the past thousand years, notably
the events of 1799, 1833, 1866 and 1966. The earliest record of Leonid activity dates back to 899.
November 1998 therefore saw astronomers preparing for a possible meteor storm during the night of
17/18 November. However, although a moderately strong shower peak was observed as predicted, the
meteor shower as a whole was dominated by the earlier appearance of hundreds of exceptionally bright
meteors, known as fireballs. These were seen by observers at European longitudes during the previous
night, 17 November, more than 16 hours ahead of the predicted peak.
In fact, meteor storms come in two types: a `normal' storm, comprising many visual meteors per
second, and explained as the result of the Earth running into particles that have been recently released
from the comet; and a `fireball' storm, in which the overall meteor count is lower but the event is
dominated by hundreds of spectacularly bright meteors or fireballs.
The 1998 event was of the second kind, and the intensity and duration of this exceptional event
indicated that the Earth must have passed through an extremely dense, narrow stream of large dust
grains, having sizes ranging up to several centimetres. The timing of the event, more than 16 hours
ahead of schedule, suggested that these dust particles occupied an orbit significantly different from that
of the main stream of small grains. The orbital difference showed that the meteoroids must have left the
11

cometary nucleus many hundreds of years ago; but it posed the question: how could the stream have
maintained its coherence and high spatial density for so long?
To solve the problem, David Asher and co­workers calculated the motion of large dust grains ejected
from the comet at each of its last 42 perihelion passages. They checked each case to see whether any of the
particles could explain the fireballs seen in 1998, and identified the perihelion passage of September 1333
as the time when most of the observed particles were released. These particles had avoided spreading out
as a result of a dynamical process known as a resonance, analogous to the mechanism leading to the fine
structure seen in Saturn's rings.
Many comets and asteroids swing around the Sun in orbits that are simple multiples of the orbital
period of Jupiter, the most massive planet in the solar system and the biggest disturbing influence on
cometary orbits. Comet Tempel­Tuttle is no exception to this rule, having entered one of these `resonant'
orbits as long ago as the seventh century AD. For every fourteen revolutions of Jupiter, comet Tempel­
Tuttle makes five, and the same relation holds true for the largest dust particles gently released by the
comet.
The large grains with average orbital periods very close to that of the comet are therefore kept in step
by the metronome effect of Jupiter's gravitational perturbations. Instead of spreading around the whole
orbit, they are concentrated into a rather short orbital arc, leading to the formation of a dense strand of
large particles, distinct from the `normal' trails of small particles, ahead of and behind the comet. The
structure of the meteoroid stream close to the comet can be visualized as rather like a telephone wire,
made up of many separate, narrow strands. These form a complex, braided structure of material within
the broader envelope of the meteoroid stream as a whole.
The calculations by David Asher and co­workers showed that in November 1998 most of the resonant
arcs missed the Earth by a wide margin, but the arc of particles released in 1333 cut right through
the Earth's orbit. What proved that this really explained the observations perfectly was that, although
an encounter with one or another trail might normally be possible at any time within a day or two of
the predicted Leonid maximum, the calculated intersection of the 1333 arc with the Earth matched the
observed fireball maximum to the hour.
This remarkable result was the first observational demonstration of one of the most important dy­
namical features of meteoroid streams associated with Halley­type short­period comets, namely the effect
of mean­motion resonances, previously studied by Emel'yanenko and Bailey. The work highlighted the
presence of fine structure within meteoroid streams, and suggested a number of important new avenues
for research. For example, the detailed variation of the meteor rate close to the time of the shower peak
could be used to infer the precise distribution in space of the meteor­producing strands, and correlating
the variations in meteor rate with changes in the meteor brightness distribution would give insight into
the history of cometary mass loss over many revolutions.
In closely related work, David Asher also explained previous Leonid meteor storms (notably the great
storms of 1833 and 1966), and together with Rob McNaught made accurate predictions for the time of
the `normal' storm trails of the Leonids. Their principal results were as follows:
ffl meteor storms generally only occur when the Earth passes within ¸100,000km of a trail of recently
released meteoroids (i.e. within ¸15 Earth radii of the centre of the trail);
ffl the predicted time of the peak of the meteor display can be improved by introducing a topographic
correction, the final results being accurate to \Sigma5 m ;
ffl the dust trails are slightly flattened in the cometary orbital plane;
ffl the 1999 Leonid shower was dominated by meteoroids comprising the 3­revolution dust trail emitted
by comet Tempel­Tuttle at its perihelion passage of 1899, peaking (for the UK) at 1999 November
18 02 h 12 m , including a topographic correction of 4 m ; and
ffl future years offer even better chances of a strong meteor shower, for example the 4­revolution trail
of meteoroids ejected from the comet in 1866 is predicted to produce a zenith hourly rate (ZHR)
? 10,000 at 2001 November 18 18 h 19 m . The first encounter of the Earth with this particular trail
occurs at 2000 November 18 07 h 51 m , with a predicted ZHR in the range 100--5,000, so the 2000
observations will be crucial to confirming or otherwise the likely meteoroid flux in 2001.
In summary, David Asher and Rob McNaught showed --- for the first time --- how to predict the timing
and strength of meteor storms, taking full account of the complexity of the dynamics and the extremely
narrow transverse dimensions in space of the recently ejected meteoroid streams.
In conclusion, it is interesting to note that good news for meteor observers can be a concern for
satellite operators. Very high speed dust impacts can cause plasma to be generated, leading in turn to
12

electrical failure in satellites. There is evidence, for example, that the Olympus communications satellite
was disabled as a result of the impact of a meteoroid from the Perseid stream in 1993.
Thus, while there is an awareness of the hazard from man­made space debris, and of the hazard
to civilization from impacts of large bodies, advance knowledge of the detailed structure of the Leonid
stream also has potential commercial value. Satellite operators could use this information to minimise
the risk from the Leonid dust trails, for example by adjusting the satellite's orbit to place the satellite
in the Earth's `shadow', or as far as possible from the centre of the dust trail, at the time of the peak
meteoroid flux. By defining the structure of these trails more accurately than ever before, Asher and
McNaught have therefore pioneered a new technique for mitigating the cometary debris impact hazard.
2.6.3 Scientific Administration
During the year, Mark Bailey was also appointed as Chair of the Astronomical Science Group of Ireland
(ASGI), for a two­year period from 1999 October 1, and as a member of the RAS Education Committee,
for a three­year period starting 1999 September 1. He was also appointed Editor­in­Chief of the journal
Earth, Moon, and Planets.
2.7 M. de Groot, Consultant Research Associate
2.7.1 Correlation between Spectroscopy and Photometry in P Cygni
Data from the Automatic Photoelectric Telescope Service in Arizona continued to be collected. A paper
analysing the photometry of P Cygni during the 20th century is in preparation in collaboration with
C. Sterken, Brussels, and A. van Genderen, Leiden.
An investigation of Hff spectroscopy and UBV photometry of P Cygni covering the period 1990 to
1994 has shown that the star varies on a number of different time­scales ranging from a few months to 7
years. The longer time­scale variations are caused by normal S Dor variations; non­radial pulsations ---
s­mode or g­mode --- are the suspected cause of the shorter time­scale variations. Real variations in the
stellar wind are found to be connected to processes in P Cygni's photosphere. A paper in collaboration
with N. Markova (Bulgaria), S. Scuderi (Italy), and N. Panagia (USA), has recently been submitted.
On the invitation of its Editor, a review article on P Cygni, in collaboration with G. Israelian (Tenerife)
was produced for Astrophysics and Space Science.
2.7.2 Investigation of the SDor Phenomenon in Luminous Blue Variables
A photometric study of j Carinae covering the period 1974 to 1998 has provided further evidence that
this star is more complex than hitherto believed: a normal S Dor variable showing both long­term (a few
years) and short­term (a few months) photometric variations seems to be surrounded by a hot luminous
disc. The nature of j Carinae is being debated in the literature and at scientific meetings. We --- de
Groot, Sterken, and Van Genderen --- do not find convincing evidence for binarity as proposed by others.
Visual observations of some 20 southern luminous blue variable stars, most of them in the Large
Magellanic Cloud, continued to be collected by Albert Jones (New Zealand) and to be made available for
analysis by a Nuffield Science Bursary student. Quasi­periodic light variations were found in several of
these stars.
2.7.3 Other Activities
During 1999, Mart de Groot served as Co­Editor of The Journal of Astronomical Data. He also delivered
a number of popular lectures in various parts of the world, and supervised two Nuffield Science Bursary
students. He is currently Chairman of the Scientific and Local Organizing Committee of the international
workshop ``P Cygni 2000: Four Hundred Years of Progress'', to be held in Armagh from 20--23 August
2000. The conference has been financially supported by sponsorship from the First Trust Bank, Armagh.
2.8 W.M. Napier, Senior Research Fellow
2.8.1 Zodiacal Cloud
The zodiacal cloud is a disc of dust orbiting within the inner planetary system. It is supplied erratically
by the disintegration of comets entering the solar system, and by dust feeding in from collisions in the
asteroid belt. The cloud can be seen at certain times of the year as a second `Milky Way' along the
ecliptic. Existing models of the zodiacal cloud have always adopted an equilibrum assumption, in which
13

the input from comet and asteroid disintegration balances the output from collisional grinding between
the dust particles and their removal by the Poynting­Robertson effect. A long­term project by Bill Napier
has been the construction of a model zodiacal cloud in which the assumption of a steady­state balance is
no longer made.
The significance of this study is that it puts into quantitative form the suggestion that the cometary
component of the zodiacal cloud is highly variable, and that in the wake of giant comet entry into a short­
period, near­Earth orbit, the dust influx to the Earth's atmosphere may acquire a climatically significant
optical depth. The output from the programme is thus intended to be an input to Mie scattering studies
of radiative transfer in the stratosphere and mesosphere, and to models of global climatic change.
This model was developed throughout 1999 to the state where quantitative results were being obtained.
The cloud is specified by a three­dimensional grid, each element of which contains the numbers of dust
particles as a function of semi­major axis, eccentricity and mass. The evolutionary pathways of dust
particles due to radiation pressure are described by fixed transition probabilities connecting the grid
elements. Other elements are absorbing states representing infall to the Sun or ejection to infinity:
particles entering these states are removed from the system. Mass is injected from the breakup of
comets entering short­period, high­eccentricity orbits at random times, and removed through collisional
disintegration, the Poynting­Robertson effect and radiation pressure.
The detailed results confirm preliminary analyses that the annual flux of cometary dust on to the
Earth may on occasion approach a million tons a year, almost two powers of ten higher than current
values. Thus the zodiacal cloud is confirmed to be a highly variable entity, a fact which will inform future
studies of climatic effect of cometary and asteroidal dust over long time­scales.
2.8.2 Quasar Redshifts
Continuing a long­standing interest in the statistical aspects of `anomalous redshift' claims, Bill Napier,
in collaboration with Geoffrey Burbidge (University of California at San Diego), has been investigating
claims that there is a periodicity of 0.089 in the log(1 + z) frequency distribution of quasars, with peaks
occurring at redshifts z = 0:06; 0:30; 0:60; 0:96; 1:41; : : : ; 4:46. This claim is about 30 years old but a
possible rationale has recently emerged in that such oscillations may be a generic feature of scalar­tensor
theories of gravity in the post­inflation phase of expansion. The claim, if confirmed, would therefore have
profound implications for cosmology. Selection effects are the major problem with this periodicity claim,
and samples were chosen with a view to minimizing these. By the end of 1999 a definitive answer to the
issue had still not been obtained.
3 Visitors and Seminars
The Observatory maintains an active visitors programme, encompassing students, postdoctoral research
assistants and more senior researchers, and hosts a research seminar approximately once per week during
the academic year. The calendar year 1999 saw working visits from 7 astronomers of postdoctoral status
or higher, with additional visits by 2 Ph.D. students based elsewhere. During 1999 Observatory staff also
supervised 7 school work­experience students, 2 A­level summer students under the Nuffield scheme, 2
QUB undergraduates on project work, 2 Trinity College Dublin (TCD) final­year undergraduate projects,
and 1 undergraduate on a summer research programme. The programme of research colloquia for 1999
(numbering 28 separate talks) is listed in Appendix D. It is notable that more than half of these seminars
were provided by external speakers.
Another aspect of the visitors programme is the high frequency of visits by members of the public
and small groups. Observatory tours are usually conducted by the Librarian, who in 1999 showed
approximately 750 individuals from 8 different countries around the Observatory. This highlights the
success of the Armagh Observatory's `open door' policy to attract small numbers of visits by interested
members of the public, groups and societies.
These visitors included tours from more than a dozen groups and societies, including the Reading
Astronomical Society, the Friends of St. Columbs Cathedral Londonderry, the Irish Science Centres
Association Network, the Irish Astronomical Society, school parties (e.g. Armagh Saints and Scholars
Integrated Primary School, the John Scottus School, Dublin), local societies (e.g. the Armagh Diocesan
Society, the Friends of St. Patrick's Church of Ireland Cathedral), and students from Queen's University
Armagh.
However, a far greater number of people now visit the Observatory electronically through the web­
site (http://www.arm.ac.uk/), in the form of `e­visitors'. The improvements in the web­site, upgraded
during 1999 by the Starlink Manager Martin Murphy and other staff (principally Michael Smith and
14

Scott Manley), have now led to a position where the Observatory attracts more than 100,000 unique
e­visitors per year, from more than 100 countries around the world. This highlights an additional role
of the Armagh Observatory, as a gateway for the promotion of Northern Ireland, and Armagh City and
District, on the world stage.
Finally, the Observatory hosted visits during 1999 by a number of VIPs and television personali­
ties. Mr Lembit ¨
Opik MP (Liberal­Democrat Spokesman for Northern Ireland) and family visited the
Observatory on 1999 March 22, to present an academic sash to the Observatory, received by him from
the Estonian Academy of Sciences on behalf of his grandfather, Dr Ernst ¨
Opik, Acting Director of the
Observatory from 1974--1976. The Minister for Education, Mr John McFall MP, visited the Observatory
on 1999 April 8; and the actress Hannah Gordon spent a day at the Observatory whilst filming the tele­
vision programme `Watercolour Challenge'. This resulted in a broadcast on 1999 October 20, featuring
interviews with Observatory staff and images of the Armagh Observatory and Astropark.
4 Public Understanding of Science
1999 included a total solar eclipse (August 11) visible from the UK mainland and a Leonid meteor storm
(November 18), both `once­in­a­lifetime' events almost guaranteed to attract media attention and to
raise public interest in astronomy. Staff at the Armagh Observatory played a major role in explaining
these phenomena to the general public, and were prominent in providing assistance as required both to
individuals and the various mass­media. The Observatory exceeded by a large margin the record set the
previous year (1998) for the total number of identified media mentions in a single calendar year, with the
result that the Armagh Observatory probably received greater coverage on the national and international
scene during 1999 than any other research group of comparable size in the UK or Ireland.
4.1 Total Solar Eclipse
Armagh Observatory staff were active in many ways. Aileen McKee, Martin Murphy, Lawrence Young
and summer student Jonathan Horner helped the Planetarium cope with the large influx of visitors on
eclipse day. Other Armagh astronomers observed the solar eclipse from various parts of Europe, ranging
from places in Cornwall (cloudy), Alderney (clear), Northern France (cloudy), to Germany, Austria,
Hungary, Bulgaria and Turkey (all clear). Reports from several of these observations were recorded in
various media, including national radio, television and newspapers. The Irish Astronomical Association
published an excellent summary of eclipse reports in the September issue of Stardust.
The Librarian's solar eclipse leaflet, prepared the previous year in readiness for the total solar eclipse
(and also distributed through the Observatory's web­page: http://www.arm.ac.uk/eclipse99.html), was
in great demand throughout the year, and a second print run was made. In total, almost 1500 hard copies
of the eclipse leaflet were distributed to individuals and various organizations, the latter including the
Royal Astronomical Society, the Royal Irish Academy, the PPARC, the English Riviera Tourist Board,
and Devon County Council.
4.2 Press, Radio and Television
The number of identified mentions of the Armagh Observatory and its staff in various mass­media has
increased from 11 in 1994 to 233 in 1999. Whilst many of these `media mentions' (about 30%) are in the
local press (e.g. the Ulster Gazette, Armagh Observer etc.), some of which have among the highest local
impact factors in the UK, a substantial number of reports occur in specialist and technical magazines,
on radio or television, or in the national and international press.
The number of identified media mentions is sufficiently large that it is of interest to consider the
breakdown versus type of publication. This is shown in Table 1. Many of these newspapers and radio or
television programmes reach millions of people simultaneously, and it is clear that many tens of millions
of people must have been exposed to `Astronomy in Armagh' during 1999.
The Observatory also issues press releases on various meteorological and astronomical topics of local
or general interest, and on news items that specifically concern Armagh Observatory staff or their research
results. In 1999, the Librarian and other staff produced 42 such media releases, of which at least 40 were
published in one form or another in the local or national press, an exceptionally high `hit' rate. In addition
to media releases, astronomer Gerry Doyle published a series of 11 articles in the local newspaper `The
Ulster Gazette', while Bill Napier's novel Nemesis, a fictionalized account of a threat asteroid, published
in paperback on December 1999, has sold a total of 50,000 copies. The book has now been translated
into German and Japanese, with sales of a similar order expected in each of these countries.
15

Programme or Medium Citations
UK and Republic of Ireland local newspapers 71
Popular astronomy and specialist magazines 33
UK national newspapers excluding Northern Ireland 30
UK local radio and Republic of Ireland radio 22
Northern Ireland and Republic of Ireland national newspapers 18
UK and Republic of Ireland national television 14
UK national radio 9
Foreign newspapers 7
Northern Ireland local television 6
Foreign radio 3
Foreign television 2
Miscellaneous items 18
Table 1: Breakdown of known media citations for 1999. The 233 identified citations include 30 reports in
UK national newspapers (e.g. Times, Guardian, Independent, Daily Telegraph, Daily Mail, Daily Express,
and corresponding Sunday papers); 18 in Northern Ireland and Republic of Ireland national newspapers
(e.g. Belfast Telegraph, Irish News, Newsletter, Irish Times, Irish Independent, Sunday Tribune); and
22 UK local radio stations (e.g. Radio Ulster, Radio Foyle, Downtown Radio and others in Britain) and
Republic of Ireland stations (RTE and local stations). The Observatory was featured 14 times on UK and
Republic of Ireland national television news and documentary programmes (e.g. BBC1, BBC2, ITV3,
ITV4, Channel 5, Sky, RTE), and 9 times on UK national radio (e.g. BBC Radio 4 Today and PM
programmes, and Radio 5). The figure of 2 citations on foreign television is obviously an extreme lower
limit, due to under­reporting.
The Librarian (and occasionally other staff) also regularly answers questions from members of the
public on different aspects of astronomy, the list for 1999 extending to 265 distinct enquiries.
4.3 Astropark
During 1999, responsibility for the Armagh Astropark was transferred from the Planetarium to the Ob­
servatory (with effect from 1999 March 24). The Observatory is committed to developing and improving
the facilities in the Armagh Astropark and seeks to improve this public facility as and when time and
other resources allow. The vision is to make the Armagh Astropark the leading outdoor exhibit for the
public understanding of science in Ireland.
Initial steps towards this objective were taken by Simon Jeffery with the completion and installation
of five Astropark display boards during early 1999, and by Lawrence Young, Shane Kelly and Colin
McKeown (Armagh Planetarium), to replace the model terrestrial planets which had previously been
vandalized or stolen. The broken central cube, part of the hyper­cube exhibit, was repaired on a temporary
basis by Colin McKeown.
4.4 History
4.4.1 Meteorological Record
During 1999, grant applications were progressed by Mark Bailey and John Butler (with the assistance of
other staff, especially Lawrence Young and Martin Murphy) to obtain external funding to widen public
access to the Observatory's long series of meteorological records which commenced on a regular basis in
1795 and continue to the present day. The applications were to enable outside users to obtain access to
scanned images of all records, and to provide access to calibrated daily data on air temperature, humidity,
rainfall, pressure and sunshine. By the end of the financial year two such applications were successful,
providing funds in future years to complete a substantial meteorological project.
The successful grants were a Heritage Lottery Fund application `Developing Access to Northern Ire­
land's Meteorological Record', to place on the internet the Observatory's 7500 pages of hand­written
meteorological records, and an Irish Sailors and Soldiers Land Trust grant `Compilation of the Irish Cli­
mate Archive', to enable the written record to be verified and calibrated and to facilitate research into
general aspects of global warming contained within the Armagh climate archive.
16

4.4.2 Heritage
As the first stage of a larger conservation and archive project, an application has also been prepared to
the Heritage Lottery Fund to restore three historic telescopes and their associated domes. One of the
telescopes, the 15­inch reflector (1834) by Grubb, is of exceptional historical interest as the first large
reflector to be mounted on an equatorial mounting with a clock drive. As such it is the forerunner of many
of the large Grubb reflectors which followed in the nineteenth and twentieth centuries. The telescope
will be rebuilt from the surviving parts and placed in its original location in the 1827 dome. The 18­inch
Calver/Schmidt telescope will also be restored, probably to its original Calver Newtonian design. This
project will be progressed by John Butler with the assistance of the architect Stephen Leighton, and
David Sinden of the Sinden Optical Company.
5 Staff
The staff position at the Armagh Observatory on 31 December 1999 is shown in Appendix A. Individuals
are identified by their 3­letter (sometimes 2 or 4) Starlink computer username (full e­mail address:
xxx@star.arm.ac.uk), together with their job­title and an indication of their principal function in the
Observatory. A high proportion of Observatory staff are involved in core research and support activities,
the entire administration being supported by only three staff (mc, ambn, lfy), one of whom (lfy) is shared
equally with the Planetarium.
5.1 Staff Movements
Mr Shane Kelly, the new Grounds and Meteorological Officer, arrived at the Observatory on 1999 October
1; and a new research student Il'ia Roussev arrived at the beginning of the year to work with Gerry Doyle
on analyses of SOHO data from the solar transition region, in particular on modelling ultraviolet explosive
events on the quiet Sun. Two new PhD students were recruited in October, namely: Tigran Khanzadian,
to work with Michael Smith on the environments of protostars; and David Garc'ia Alvarez, to work jointly
with John Butler and Gerry Doyle on modelling flares on late­type stars.
One new PPARC PDRA grant came into effect during the year, namely that relating to Vincent M.
Woolf. Dr Woolf arrived in 1999 July, to work with Simon Jeffery on `Pulsations in Early­Type Stellar
Remnants'. One other PDRA, namely Dipankar Banerjee, left the Observatory early in 2000 to take up
an appointment at the University of Leuven, Belgium. Dr Banerjee organized the Observatory seminars
during 1999.
Two students, namely Darko Jevremovi'c and Elena P'erez P'erez, successfully defended their PhD
theses. The respective subjects were: `Hydrogen Balmer Lines in Stellar Flares', and `Dynamic Events
in the Solar Atmosphere'.
6 Research Activity and Funding Trends
The scientific output and research activity of Armagh Observatory staff over the past seven years are
summarised in Table 2. During this period, virtually all relevant performance indicators show a significant
improvement: the number of refereed journal publications has trebled, the amount of external income
has increased by a factor greater than five, and the number of identified media citations has increased by
a factor greater than twenty.
However, Table 2 also highlights a worrying trend, namely a significant real­term decrease in the
amount of DENI/DCAL funding. Without increased core funding, it will not be possible to maintain
the positive trends seen in the above performance indicators; research activity at the Observatory will
decline; and the fruits of the substantial financial and intellectual investment in astronomy at Armagh
since the mid­1980s will have been wasted.
The 1998 Annual Report closed with a number of `Items of Concern', the first of which concerned the
issue of access to a sufficiently high bandwidth connection to the internet through the Joint Academic
Network (JANET). The difficulty of resolving this issue may be attributed in part to funding issues, in
part to the Observatory's unique status in the UK academic/research scene. The interests and objectives
of the Armagh Observatory do not appear to fit closely with the strategic aims of any single Northern
Ireland government department, but it is important that the Observatory should not be penalised by
`falling between stools'.
In fact, compared to its position a decade ago, the Observatory has `lost' a number of funding pos­
sibilities in comparison with opportunities open to other similar institutions and research groups in the
17

External Refereed Identified Total DENI DENI Income
Financial Year Grant Income Journal Media Grant­in­Aid Normalised to
($000s) Publications Citations ($000s) 1993/1994 prices
1993/1994 35 13 -- 445.0 445.0
1994/1995 58 22 11 425.6 414.9
1995/1996 172 19 14 468.5 442.1
1996/1997 264 45 45 480.0 442.3
1997/1998 275 42 108 473.2 425.7
1998/1999 195 43 147 443.0 383.1
1999/2000 293 32 233 458.5 390.2
Table 2: Increase in research activity over the years. The numbers of refereed journal publications and
identified media citations refer to the corresponding calendar year (e.g. publications in financial year
1999/2000 corresponds to calendar year 1999). The total external income in 1999/2000 was $305k.
The sixth column shows the value of the announced grant­in­aid for each financial year normalised to
1993/1994 prices, the values being corrected for rising costs by the Retail Prices Index. This under­
estimates the effects of salary inflation and other unavoidable additional running costs. The DCAL
grant­in­aid for 2000/2001 has been announced at $458.5k, equivalent to only $380.3k at 1993/1994
prices.
UK. These include: (1) the lack of a Northern Ireland research studentship quota following the transfer,
in the early 1990s, of research studentship funds from the SERC to the DENI; (2) the replacement, in
the mid­1990s, of a primary connection to the JANET with a `sponsored' connection through QUB at a
much lower bandwidth (256 kbps) than that (2 Mbps) available to a university department; (3) the lack
of any funding uplift in proportion to RAE­assessed improvement in 1996; (4) the omission in 1999 of
the Observatory from plans to extend JANET access to both universities and FE colleges in Northern
Ireland, and exclusion from plans for a high­bandwidth Northern Ireland Municipal Area Network; and
(5) the apparent omission of the Observatory from funding opportunities under the JREI from 2000,
when (under the DENI) it was eligible in 1999.
It seems important to underline with clarity the nature of the current threat, due to underfunding
and other factors, to the continuing success of the Observatory. The following remarks are taken from
the conclusion of the Operational Plan for 1999/2000 3 , prepared at the start of this 1999 reporting year.
Finding a resolution of the funding problem was identified as the key strategic issue to be progressed
during 1999.
``Looking to the future, irrespective of whether the government decides to fund a UK Spaceguard
programme, it is essential that the Observatory should continue to strengthen its research capability.
The alternative is to shrink, putting us in a weaker position for participation in the 2001 Research
Assessment Exercise, and facing eventual decline. It is well known that the Observatory has not
benefitted from any additional funding since the 1996 RAE, proportional to its improvement between
the 1992 and 1996, and that this together with the rather flat funding regime of the past five or
six years presents a rather dismal outlook for the future. Despite the enormous increase in research
productivity indicated in Table 1 [see Table 2 above], the Observatory's total DENI grant­in­aid for
1999/2000 is virtually identical in cash terms to that given in 1992/1993. It cannot be emphasized
too strongly that this cut in funding, in real terms, combined with the accumulation of unavoidable
additional costs (e.g. the internal audit, salary inflation and a greater NILGOSS employer's pension
contribution), has now reached a point where the Observatory may, within a few years, be facing a
crisis comparable only to the long­term decline of the 1920s and 1930s, following the resignation of
Dr J.L.E. Dreyer.
In short, the issue of chronic underfunding of the Observatory must be resolved. Compared to
this, the other objectives that we seek to achieve during the coming financial year are relatively
straightforward. The Observatory must convince the new Northern Ireland executive to continue
its past, generous investment in astronomy, and to provide the Observatory with a sufficient level
of funding to recruit and retain the number of senior research and support staff necessary for it
to operate efficiently and influentially both on the UK and international astronomical stage. The
Observatory has a rich heritage and can make an immense contribution to the cultural, economic and
social life of the community.''
3 The Armagh Observatory and Planetarium Operational Plan 1999/2000, April 30, 1999
18

A Armagh Observatory Staff 1999
Title, Name and Starlink Username Position Notes Base Cost
Centre
1 Professor Mark E. Bailey meb Director OBS OBS
2 Dr C. John Butler cjb Research Astronomer OBS OBS
3 Dr John E. Chambers jec Research Astronomer OBS OBS
4 Professor J. Gerry Doyle jgd Research Astronomer OBS OBS
5 Dr C. Simon Jeffery csj Research Astronomer OBS OBS
6 Dr Michael D. Smith mds Research Astronomer OBS OBS
7 Dr Bill M. Napier wmn Senior Research Fellow OBS OBS
8 Mr Geoff Coxhead gc Software/Hardware Support OBS OBS
9 Mr H. Martin Murphy hmm Starlink Manager OBS OBS
10 Mrs Margaret Cherry mc Accounts Officer OBS OBS
11 Mr Shane T. Kelly stk Grounds/Meteorological Officer OBS OBS
12 Mr John McFarland jmf Librarian/PRO/Archivist OBS OBS
13 Mrs Aileen McKee ambn Secretary/Admin. Support OBS OBS
14 Mr Lawrence F. Young lfy Joint Administrator OBS/PLA OBS/PLA
15 Dr David J. Asher dja Postdoctoral Research Assistant PPARC OBS OBS
16 Dr Dipankar Banerjee dipu Postdoctoral Research Assistant OBS OBS
17 Mr Darko Jevremovi'c djc Postdoctoral Research Assistant PPARC OBS OBS
18 Dr Armin Theissen ath Postdoctoral Research Assistant PPARC OBS OBS
19 Dr Vincent M. Woolf vmw Postdoctoral Research Assistant PPARC OBS OBS
20 Ms Sandra V. Jeffers svj Research Student (MPhil) F/T QUB OBS OBS
21 Mr David Garc'ia Alvarez dga Research Student (PhD) P/T QUB OBS OBS
22 Mr Enric Pall'e Bag'o epb Research Student (PhD) P/T QUB OBS OBS
23 Ms Regina Aznar Cuadrado rea Research Student (PhD) P/T QUB OBS OBS
24 Mr Tigran Khanzadian tig Research Student (PhD) P/T QUB OBS OBS
25 Mr Scott P. Manley spm Research Student (PhD) P/T QUB OBS OBS
26 Mr Kassios Mitrou kam Research Student (PhD) P/T Athens Self OBS
27 Mr Ferhat F. Ozeren ffo Research Student (PhD) F/T Ankara OBS OBS
28 Ms Elena P'erez P'erez epp Research Student (PhD) P/T QUB OBS OBS
29 Ms Pilar Monta~n'es Rodr'iguez pmr Research Student (PhD) P/T QUB OBS OBS
30 Mr Il'ia Iankov Roussev ilr Research Student (PhD) P/T QUB OBS OBS
31 Mr Jim V. Scotti jvs Research Student (PhD) P/T QUB Tucson OBS
32 Mr P. Nick Sleep Research Student (PhD) P/T Open Univ. Home Self
33 Mr Luca Teriaca lte Research Student (PhD) P/T QUB OBS OBS
Dr Mart J.H. de Groot mdg Consultant Research Associate Retired Home OBS
Armagh Observatory staff position at 1999 December 31.
19

B Board of Governors and Management Committee 1999
B.1 Board of Governors
The Board of Governors comprises the Church of Ireland Archbishop of Armagh (Chairman), the Dean
and Chapter of the Church of Ireland Cathedral of Armagh, 1 DENI nominee, 1 QUB nominee, and up
to 3 additional members nominated by the Governors.
ffl Chairman: His Grace, The Most Reverend Dr R.H.A. Eames, The Lord Archbishop of Armagh
ffl The Very Reverend Dean H. Cassidy, Armagh
ffl The Venerable Archdeacon R.G. Hoey, Newry
ffl The Reverend Canon J.M. Barton, Newry
ffl The Reverend Canon A. Dawson, Cookstown
ffl The Reverend Canon C.F. Moore, Whitecross
ffl The Reverend Canon H.J.W. Moore, Cookstown
ffl The Reverend Canon R.J.N. Porteus, Cookstown
ffl The Reverend Canon F.D. Swann, Dungannon
ffl The Reverend Canon W.R. Twaddell, Portadown
ffl Professor A.E. Kingston, Queens University Belfast (QUB Nominee)
ffl Dr E. Haughey, Ballyedmond Castle, Rostrevor (Governors Nominee)
ffl Professor Sir Martin Rees, Astronomer Royal, IoA Cambridge (Governors Nominee)
ffl Professor D. Lynden­Bell, IoA Cambridge (Governors Nominee)
B.2 Management Committee
The Management Committee comprises the Church of Ireland Archbishop of Armagh or his nominee
(Chairman), 3 members of the Board of Governors, 4 DENI nominees, 1 QUB nominee, 1 PPARC
nominee, 1 DIAS nominee, and up to 4 additional members nominated by the Governors.
ffl Chairman: His Grace The Most Reverend Dr. R.H.A. Eames, The Lord Archbishop of Armagh
ffl The Venerable Archdeacon R.G. Hoey, Newry (Board of Governors)
ffl Professor A.E. Kingston, Queens University Belfast (Board of Governors)
ffl Professor D. Lynden­Bell, IoA Cambridge (Board of Governors)
ffl Professor A.E. Roy, University of Glasgow (DENI Nominee)
ffl Professor P.L. Dufton, Queens University Belfast (QUB Nominee)
ffl Professor M.S. Merrifield, University of Nottingham (PPARC Nominee)
ffl Professor L. Drury, Dublin Institute for Advanced Studies (DIAS) (DIAS Nominee)
ffl Dr F.N. Byrne (Deputy Chairman), Ballynahinch (Governors Nominee)
ffl Sir Kenneth Bloomfield, Chairman NIHEC (Governors Nominee)
ffl Professor D.A. Williams, University College London (Governors Nominee)
ffl Mr D.J. Clement, Antrim (Governors Nominee)
20

C Refereed Journal Publications 1999
1. Albayrak, B., ¨
Ozeren, F.F., Ekmekci, F., Demircan, O., 1999, ``Period variation of six RSCVn­
type binaries with possible light­time effect'', Rev. Mex. Astron. Astrofis., 35, 3--12.
2. Amado, P.J., Butler, C.J., Byrne, P.B., 1999, ``Photometric modelling of starspots --- I. A
Barnes­Evans­like surface brightness­colour relation using I c -- K'', MNRAS, 310, 1023--1032.
3. Asher, D.J., 1999, ``The Leonid meteor storms of 1833 and 1866'', MNRAS, 307, 919--924.
4. Asher, D.J., Bailey, M.E., Emel'yanenko, V.V., 1999, ``The resonant Leonid trail from 1333'',
Irish Astron. J., 26, 91--93.
5. Asher, D.J., Bailey, M.E., Emel'yanenko, V.V., 1999, ``Resonant meteoroids from Comet
Tempel­Tuttle in 1333: the cause of the unexpected Leonid outburst in 1998'', MNRAS, 304,
L53--L56.
6. Bailey, M.E., Napier, W.M., ``The fluctuating population of Earth impactors'', J. Brit. Inter­
planet. Soc., 52, 185--194.
7. Chambers, J.E., 1999, ``A hybrid symplectic integrator that permits close encounters between
massive bodies'', MNRAS, 304, 793--799.
8. Chambers, J.E., 1999, ``N­body simulations of planet formation: varying the initial number of
planetary embryos,'' Earth, Moon & Planets, 81, 3--6.
9. Davis, C.J., Smith, M.D., Eisl¨offel, J., Davies, J.K., 1999, ``Excitation and kinematics in H 2 bow
shocks: near­infrared observations of HH 99 and VLA 1623A (HH 313)'', MNRAS, 308, 539--550.
10. Doyle, J.G., Keenan, F.P., Ryans, R.S., Aggarwal, K.M., Fludra, A., 1999, ``Electron densities
above a polar coronal hole based on improved Si IX density diagnostics'', Solar Physics, 188, 73--80.
11. Doyle, J.G., Teriaca, L., Banerjee, D., 1999, ``Coronal hole diagnostics out to 8R fi '', A&A,
349, 956--960.
12. Doyle, J.G., van den Oord, G.H.J., O'Shea, E., Banerjee, D., 1999, ``Exploring the dynamical
nature of the lower solar chromosphere'', A&A, 347, 335--347.
13. Friedrich, S., Koester, D., Heber, U., Jeffery, C.S., Reimers, D., 1999, ``Analysis of UV and optical
spectra of the helium­rich white dwarfs HS 2253+8023 and GD 40'', A&A, 350, 865--874.
14. Gunn, A.G., Brady, P.A., Migenes, V., Spencer, R.E., Doyle, J.G., 1999, ``Eclipsing behaviour of
the radio emission in the Algol system V505 Sagittarii'', MNRAS, 304, 611--621.
15. Israelian, G., de Groot, M., 1999, ``P Cygni: an extraordinary luminous blue variable'', Space Sci.
Rev., 90, 493--522.
16. Jeffery, C.S., Hill, P.W., Heber, U., 1999, ``The chemical composition of the pulsating helium star
V652 Her'', A&A, 346, 491--500.
17. Jeffery, C.S., Saio, H., 1999, ``Non­adiabatic linear pulsation models for low­mass helium stars'',
MNRAS, 308, 221--227.
18. Kameswara, R.N., Lambert, D.L., Adams, M.T., Doss, D.R., Gonzalez, G., Hatzes, A.P., Ren'ee,
J.C., Johns­Krull, C.M., Earle, L.R., Pandey, G., Reinsch, K., Tomkin, J., Woolf, V.M., 1999,
``The 1995--96 decline of RCoronae Borealis: high­resolution optical spectroscopy'', MNRAS, 310,
717--744.
19. Kilkenny, D., Koen, C., Jeffery, C.S., Hill, N.C., O'Donoghue, D., 1999, ``The pulsating hydrogen­
deficient star LSS 3184 (BX Cir)'', MNRAS, 310, 1119--1127.
20. L¨obel, A., Doyle, J.G., Bagnulo, S., 1999, ``Modelling the spectral energy distribution and SED
variability of the Carbon Mira RFornacis'', A&A, 343, 466--476.
21. McNaught, R.H., Asher, D.J., 1999, ``Variation of Leonid maximum times with location of ob­
server'', Meteoritics & Planet. Sci., 34, 975--978.
21

22. McNaught, R.H., Asher, D.J., 1999, ``Leonid dust trails and meteor storms'', WGN, Journal of
the Int. Meteor Org., 27, 85--102.
23. ¨
Ozeren, F.F., Doyle, J.G., Jevremovi'c, D., 1999, ``The Wilson­Bappu relation for RSCVn
stars'', A&A, 350, 635--642.
24. P'erez, M.E., Doyle, J.G., Erd'elyi, R., Sarro, L.M., 1999, ``Explosive events in the solar atmo­
sphere'', A&A, 342, 279--284.
25. P'erez, M.E., Doyle, J.G., O'Shea, E., Keenan, F.P., 1999, ``Temporal variability in the electron
density at the solar transition region'', A&A, 351, 1139--1148.
26. Sarro, L.M., Erd'elyi, R., Doyle, J.G., P'erez, M.E., 1999, ``Modelling explosive events in the
solar atmosphere'', A&A, 351, 721--732.
27. Teriaca, L., Banerjee, D., Doyle, J.G., 1999, ``SUMER observations of Doppler shift in the
quiet Sun and in an active region'', A&A, 349, 636--648.
28. Teriaca, L., Doyle, J.G., Erd'elyi, R., Sarro, L.M., 1999, ``New insight into transition region
dynamics via SUMER observations and numerical modelling'', A&A, 352, L99--L102.
29. van Genderen, A.M., Sterken, C., de Groot, M., Burki, G., 1999, ``Photometric behaviour of Eta
Carinae, a celestial Chinese lantern'', A&A, 343, 847--860.
30. V¨olker, R., Smith, M.D., Suttner, G., Yorke, H.W., 1999, ``Numerical hydrodynamic simulations
of molecular outflows driven by Hammer jets'', A&A, 343, 953--965.
31. Woolf, V.M., Lambert, D.L., 1999, ``Three very young Hg­Mn stars in the Orion OB1 Associa­
tion'', ApJ, 520, L55--L58.
32. Woolf, V.M., Lambert, D.L., 1999, ``Mercury elemental and isotopic abundances in Mercury­
Manganese stars'', ApJ, 521, 414--431.
22

D Armagh Observatory Seminars 1999
23

E Talks by Armagh Observatory Staff 1999
Date
Speaker
Location
Title
1999
J.
McFarland
Armagh
Observatory
49
Tours
of
Armagh
Observatory
Given
in
1999
1999
C.S.
Jeffery
Professur
Astrophysik,
Universitat
Potsdam,
Germany
Stellar
Remnants:
Chemical
Evolution
and
Binary
Companions
Jan
1999
J.E.
Chambers
Nice,
France
Making
the
Terrestrial
Planets
Wed
20
Jan
1999
M.
De
Groot
Sao
Paulo,
Brazil
The
Origin
and
Future
of
the
Universe
Sat
6
Feb
1999
M.E.
Bailey
Irish
Physics
Student
Association
Meeting,
QUB
The
Increasing
Threat
from
Space
Wed
3
Mar
1999
M.E.
Bailey
Press
Conference,
House
of
Commons,
London
The
Impact
Hazard
Wed
10
Mar
1999
M.D.
Smith
Tautenburg
Observatory,
Germany
The
Unification
Scheme
for
Protostellar
Outflows:
Version
3
Wed
17
Mar
1999
C.J.
Butler
Royal
Meteorological
Society,
Imperial
College,
London
Solar
Signals
in
Climate
Data
Sat
20
Mar
1999
S.V.
Jeffers
Armagh
Planetarium,
Mothers
&
Daughters
Day
Earth
in
the
Cosmic
Shooting
Gallery
Sat
20
Mar
1999
M.E.
Bailey
COSMOS
99,
Tullamore
Astron.
Soc.,
Tullamore
The
Increasing
Threat
from
Space:
Comets,
Asteroids
and
NEOs
Apr
1999
E.
Pall' e
Bag' o
EGS
Meeting
1999,
The
Hague,
The
Netherlands
Sunshine
Records
from
Ireland,
Cloud
Factors
and
their
Link
to
Solar
Activity
and
Cosmic
Rays
Fri
9
Apr
1999
J.G.
Doyle
ASGI
Meeting,
Galway
Irish
Telescopes
Fri
9
Apr
1999
D.J.
Asher
ASGI
Meeting,
Galway
The
1998
Leonid
Fireball
Outburst
Fri
9
Apr
1999
E.
Pall' e
Bag' o
ASGI
Meeting,
Galway
An
Investigation
into
Sunshine
Records
from
Ireland
and
their
Link
to
Solar
Variability
Mon
12
Apr
1999
D.J.
Asher
Leonid
MAC
Workshop,
NASA
Ames,
USA
Modelling
of
the
Leonid
Meteor
Shower
Tue
27
Apr
1999
M.D.
Smith
Dunsink
Observatory
The
Violent
Birth
of
Stars
May
1999
J.G.
Doyle
Keynote
presentation
on
SOHO
Workshop,
Paris
Coronal
Hole
Diagnostics
Thu
6
May
1999
C.S.
Jeffery
Armagh
Observatory
Helium
Stars
in
the
Galaxy
Mon
10
May
1999
M.E.
Bailey
PASEG
Meeting,
House
of
Lords,
London
Near­Earth
Objects:
Origin,
Collision
Rate
and
Actuarial
Risk
Thu
13
May
1999
D.
Banerjee
Armagh
Observatory
Solar
Eclipses
Fri
14
May
1999
M.E.
Bailey
Royal
Astronomical
Society,
London
Fireballs
from
Comet
Tempel­Tuttle:
A
Blast
from
the
Past
Thu
20
May
1999
L.
Teriaca
Armagh
Observatory
Line
Shifts
in
the
Solar
Atmosphere
Wed
16
Jun
1999
H.M.
Murphy
Armagh
Observatory
(Joint
talk
with
Scott
Manley)
Computer
and
Network
Security
Mon
28
Jun
1999
S.P.
Manley
NISTRO
Pupil
Science
Initiative,
King's
Hall,
Belfast
Earth
in
the
Cosmic
Shooting
Gallery
Jul
1999
J.E.
Chambers
Stanford
University,
California,
USA
Planet
Formation
Thu
29
Jul
1999
C.J.
Butler
South
African
Astronomical
Observatory
GlobalWarming
---
Man
or
Nature?
Aug
1999
M.
de
Groot
Perrenport,
Cornwall
6
Lectures
on
the
Total
Solar
Eclipse,
and
the
Origin
and
Future
of
the
Universe
Presentations
by
Armagh
Observatory
staff,
1999
January
1
to
1999
August
31.
24

Date
Speaker
Location
Title
Sep
1999
J.E.
Chambers
NASA
Ames
Research
Center,
California
Meet
the
Postdocs
Sep
1999
J.E.
Chambers
NASA
Ames
Research
Center,
California
Planets
in
the
Asteroid
Belt
Wed
8
Sep
1999
D.J.
Asher
Queen's
University
Belfast
Dust
Trail
Dynamics
and
Meteor
Storm
Fri
17
Sep
1999
C.J.
Butler
ASGI
Meeting,
Dublin
Patrick
Wayman
and
Irish
Astronomical
Observing
Facilities
Fri
17
Sep
1999
C.S.
Jeffery
ASGI
Meeting,
Dublin
Observations
of
Hot
Subdwarfs
from
the
La
Palma
Observatory
Fri
17
Sep
1999
W.M.
Napier
Cesena,
Italy
Periodicity
in
the
Redshift
Distribution
of
Quasars
Mon
20
Sep
1999
M.D.
Smith
Goettingen,
Germany
The
Evolution
of
the
Environments
of
Proto­Brown
Dwarfs
Tue
21
Sep
1999
J.
McFarland
Markethill
High
School,
Elim
Church
Astronomy
(Practical)
­
I
Fri
24
Sep
1999
D.J.
Asher
International
Meteor
Conference,
Frasso
Sabino
Italy
Predicting
Leonid
Meteor
Storms
Tue
28
Sep
1999
J.
McFarland
Markethill
High
School,
Elim
Church
Astronomy
(Practical)
­
II
Oct
1999
J.E.
Chambers
Abano,
Italy
Planets
in
the
Asteroid
Belt
Mon
4
Oct
1999
J.
McFarland
East
Antrim
Astron.
Soc.,
Ballyrobert,
Co.
Antrim
The
Ingenious
Mr
(Kenny)
Edgeworth
Mon
4
Oct
1999
J.
McFarland
East
Antrim
Astron.
Soc.,
Ballyrobert,
Co.
Antrim
The
Bible
and
Astronomy
Wed
6
Oct
1999
M.
de
Groot
Takoma
Park,
Maryland,
USA
The
Origin
and
Future
of
the
Universe
Wed
6
Oct
1999
S.V.
Jeffers
Armagh
Observatory
Comparing
the
Lunar
Cratering
and
the
Small
Near­Earth
Asteroid
Size
Distribution
Thu
7
Oct
1999
V.M.
Woolf
Armagh
Observatory
Mercury
in
Hg­Mn
Stars
Fri
8
Oct
1999
S.V.
Jeffers
Royal
Astronomical
Society,
London
Comparing
the
Lunar
Cratering
and
the
Small
Near­Earth
Asteroid
Size
Distribution
Sun
10
Oct
1999
D.J.
Asher
Whirlpool
Star
Party,
Birr
Leonid
Dust
Trails
and
Meteor
Storms
Wed
13
Oct
1999
D.J.
Asher
Liverpool
John
Moores
University,
Liverpool
Accurate
Predictions
of
Leonid
Meteor
Storms
Tue
19
Oct
1999
J.
McFarland
Markethill
High
School,
Elim
Church
Astronomy
(Practical)
­
III
Tue
19
Oct
1999
M.D.
Smith
MPIA,
Heidelberg,
Germany
The
Shocks
in
Supersonic
Turbulence
Wed
20
Oct
1999
D.J.
Asher
Irish
Astronomical
Association,
Belfast
The
Leonid
Meteor
Storm
Sat
30
Oct
1999
M.
de
Groot
Annual
Meeting
of
AMALF,
Normandie,
France
Origine
et
Future
de
l'Univers
Wed
3
Nov
1999
D.J.
Asher
Armagh
Planetarium
The
Leonids:
Can
Meteor
Storms
be
Predicted?
Wed
3
Nov
1999
M.D.
Smith
Irish
Astronomical
Association,
Belfast
The
Birth
of
a
Star:
a
Spectacular
Display
of
Jets
and
Shocks
Mon
8
Nov
1999
D.J.
Asher
Astronomy
Ireland,
Dublin
The
History
of
Meteor
Astronomy
and
Coming
Leonid
Storms
Tue
9
Nov
1999
J.
McFarland
Markethill
High
School,
Elim
Church
Astronomy
(Practical)
--
IV
Fri
12
Nov
1999
M.E.
Bailey
Royal
Astronomical
Society,
London
Predictions
of
a
Fine
Display
of
Leonids
on
18
November
1999
Sat
13
Nov
1999
D.J.
Asher
The
1999
Jordanian
Leonid
Meteors
Conference
Dynamics
of
Leonid
Dust
Trails
(The
Cause
of
Storms)
Mon
15
Nov
1999
C.S.
Jeffery
Tohoku
University,
Sendai,
Japan
The
Evolutionary
Status
of
Hydrogen­Deficient
Stellar
Remnants
Mon
22
Nov
1999
C.S.
Jeffery
Gunma
Observatory
Workshop
on
Binary
and
Variable
Evolutionary
Constraints
Imposed
by
Pulsations
in
Extreme
Helium
Stars
Stars,
Gunma
Astronomical
Observatory,
Gunma
Wed
24
Nov
1999
C.S.
Jeffery
Dept.
of
Astronomy,
Tokyo
University,
Japan
Evolutionary
Constraints
Imposed
by
Pulsations
in
Extreme
Helium
Stars
Thu
2
Dec
1999
M.D.
Smith
Armagh
Observatory
Astrophysical
Turbulence
Fri
3
Dec
1999
C.S.
Jeffery
Armagh
Planetarium
The
Star
of
Bethlehem
Mon
6
Dec
1999
M.D.
Smith
Tautenburg
Observatory,
Germany
The
Signatures
of
Supersonic
Turbulence
in
Star
Forming
Regions
Mon
6
Dec
1999
C.S.
Jeffery
Armagh
Observatory
Evolutionary
Contstraints
Imposed
by
the
Pulsations
in
Extreme
Helium
Stars
Tue
7
Dec
1999
C.J.
Butler
Physics
Department,
Imperial
College,
London
Sunshine,
Clouds
and
Cosmic
Rays
Mon
13
Dec
1999
C.S.
Jeffery
Armagh
Planetarium
The
Star
of
Bethlehem
Presentations
by
Armagh
Observatory
staff,
1999
September
1
to
1999
December
31.
25

F Identified Media Mentions 1999
26