... Armagh Planetarium . ... Universe . ... 25 Comments Space is something that fascinates many.€а Every day there are technological advances, new research being carried out and even historical space related anniversaries.€а Where would we be without those valuable [ ] . ... No Comments A new image from the European southern ObservatoryтАЩs Visible and Infrared Survey Telescope for Astronomy €а(VISTA) telescope reveals the glowing clouds of gas and filaments of dust surrounding hot young [ ] . ...

... Possible Jet Blown Shells Near Microquasar Cygnus X1 . ... Credit Copyright: Steve Cullen (lightbuckets.com) Explanation: What happens to matter that falls toward an energetic black hole? ... Confirmation that black hole jets may create expanding shells has come recently from the discovery of shells surrounding Cygnus X-1 . Pictured above on the upper right is one such shell quite possibly created by the jet of microquasar and black hole candidate Cygnus X-1 . ... Herschel s Cygnus X . ...

... 2009 June 8 . Possible Jet Blown Shells Near Microquasar Cygnus X-1 . ... In the case of Cygnus X-1 , perhaps little of that matter actually makes it in. ... Confirmation that black hole jets may create expanding shells has come recently from the discovery of shells surrounding Cygnus X-1 . Pictured above on the upper right is one such shell quite possibly created by the jet of microquasar and black hole candidate Cygnus X-1 . ... About APOD | ...

... Following a micrometeoritic impact in Rev.#961 (March 2005), a new hot column appeared, whose effects leak across the whole column RAWX=318 . While a correction for this hot column is possible and implemented for MOS1 exposures taken in Imaging Mode, the offset value in MOS1 exposures taken in Timing Mode is too high for any meaningful correction to be possible. ... mos1.evt is the name of the MOS1 event list . ... RAWX in [320:329])" . ... Calculate the effective area due to the excised columns . ...

IBIS Data Analysis . ... IBIS . ... Flat Fielding - Introduction . The images obtained by IBIS will have intensity variations across the field of view that are not due to the solar image, but rather caused by instrumental effects that alter the observed intensity in each point of the field of view. ... IBIS Flat Fielding Techniques . ... Therefore, it is desirable to obtain the flat field measurements center on a point along the equator near the heliographic center of the solar disk. ...

Previous] [Up] . Given that spectra produced by GHRS are tilted across the diode array and that there are drifts with time which, it is very important that the nominal SPYBAL not be frivolously omitted. While the possible negative effects of not performing SPYBALS can be minimal for some wavelength/grating combinations, these effects are not readily predictable since they appear to be correlated with the recent thermal history of the instrument. ... GHRS Instrument Science Report 072 . ...

Acutance . ... Crane proposes a more useful measure of accutance. To measure acutance, first the extent of the edge is found by determining two point E1 and E2 where the gradient is very low. ... The acutance is given as . ... Image Edge Profile (IEP) Acutance can be measured by determining the edge profile at the normal to an edge boundary. where m is the mean derivative of the jth boundary pixel and f(i), b(i), i 1,2,3,4 .. are the foregraound and the background pixels along the normal. ...

... ConcepTests are multiple choice questions which the students pose to each other in small groups, during class. ... We are compiling a library of ConcepTests for introductory college astronomy. ... If you are a grad student or faculty member interested reviewing/editing of (at least 50) ConcepTest questions, I am offering an acknowledgment in the book or 30cents a question, whichever you prefer. ... Back to Paul Green's Science Education page. Back to Paul Green's HomePage . ...

... Today this year's largest group of sunspots will cross the Sun's central meridian. ... The next day, the number of spots in the group reached five, and the day after, on June 2nd, it was possible to count thirteen sunspots on solar disk, which had been clear prior to this. ... This year's two most powerful active areas, which passed across the solar disk at the beginning of May, 2009, are set to appear in the Sun's eastern sector in two days, on June 6th. ...

... Gravitational wave search provides insights into galaxy evolution and mergers . ... Is it possible that the gravitational effects attributed to dark matter could be caused by Jupiter-sized planets discovered orbiting other stars and also floating freely outside planetary systems? ... A large number of detected and undetected Jupiter-sized planets could not mimic the gravitational effects produced by dark matter for two reasons. ... Get instant access to subscriber content on Astronomy.com! ...

Next: Conclusions Up: Selection Effects Previous: Inconsistent (or Inconsistently Applied) . Another possible bias, present in this as well as all other surveys which use spectral indices based upon nonsimultaneous data in their selection process, is due to variability. ... In order to minimize the effect of non-simultaneous radio survey data upon our samples, we decided to expand the common definition of flat-spectrum radio sources to extend to (instead of 0.5). ...

... Records were made this January when the RadioAstron satellite was joined by ground-based telescopes, forming a radio telescope 220,000 km across тАУ roughly 20 times larger than the Earth. RadioAstron , a Russian orbital telescope of 10 meter diameter, joined with ground-based observatories to resolve objects 50 times smaller than is possible with the Hubble Space Telescope. ... Images: . The RadioAstron spaceantenna observes a celestial radio source simultaneously with ground-based dishes. ...

Disastrous earthquakes happen 100 to 200 times a year. ... There is a chance that the data of ionospheric plasma observations hold an answer to the latter question. Satellites and ground-based facilities may detect earthquake precursors in the ionosphere a few hours or days before the main shock. ... ULF "Hz"-oscillations have been recorded several hours before the main shock in a narrow magnetic field tube (40...100 km along the satellite trajectory) conjugated with epicenter of the earthquake. ...

PAGE 4 Climate Change - A Personal View By Dr John Butler, Armagh Observatory Photograph taken by Karl Jordan Photograph taken by Ciara Stephens Few people in the western world, or indeed further afield, can now be unaware of the concern expressed in the media about the possible effects of climate change and, in particular, of global warming. ... So where are we now after a decade when there was so much discussion, hype and media attention given to global warming and its cause? ...

TOWARDS SUPERSENSITIVE BOLOMETERS AND ELECTRON COOLERS BASED ON CARBON NANOTUBES M.TARASOV, J.SVENSSON, S.DITTMER, L.KUZMIN, AND E.CAMPBELL Chalmers University of Technology, GЖteborg SE 41294, Sweden E-mail: Mikhail.tarasov@mc2.chalmers.se Carbon nanotubes (CNT) are being intensively developed for novel electronics. Electron cooling by superconductor-insulator-nanotube (SIN) tunnel junctions could be extremely effective due to the small volume of the CNT. ...

The Square Kilometre Array - An Australian Perspective Dr Peter J Hall, CSIRO SKA Program Leader and Chairman, International SKA Engineering & Management Team e-mail: Peter.Hall@atnf.csiro.au The Square Kilometre Array (SKA) is a next-generation radio telescope expected to be completed by 2015. ... Many early Universe studies will be unique to the SKA and flow from its capacity to see the weak, highly Doppler-shifted, quasi-CW, radio emission from hydrogen - the most abundant element in the Universe. ...

... Obviously, the size of the cavern is of the order of the Schwartzman radius. ... Thus, consideration of the inverse effect of pulsar radiation on the properties of accreting plasma makes the ejection possible even when the Schwartzman radius is smaller than the capture radius. ... If the cavern radius , the condition at its boundary can be written as . ... Apart from magnetic dipole radiation, the cavern may also contain relativistic particles (which are also reflected from the cavern boundary). ...

Perhaps the greatest theoretical achievement of physics in the 19th century was the discovery of electromagnetic waves. ... It is possible to use this to define a unit of electric charge, as the charge which repels a similar charge at a distance of, say, 1 meter, with a force of unit strength (actual formulas make this precise). ... But "field" originally only meant the force a magnet or an electric charge could expect at a point in space, if it were placed there. ...

... Forum . ... Matias Griese - Developement . Florian Dal Fitto - Developement . Joshua Weiss - Design and Developement . Jelle Kok - Design and Testing . ... Michael Russell - Forum Moderation and Documentation . Richard Binder - Forum Moderation and Testing . Sami Haaranen - Forum Moderation and Testing . Joe Collins - Forum Moderation and Testing . ... The Kunena Team would like to thank the community for its help and support. ... Powered by Kunena Forum . ... MAO NASU . ...

... Spectroscopy of Semiconductors and Dielectrics . ... Interband optical transitions and their optical properties. ... Excitons in crystals. ... Collective interaction effects in exciton and nonequilibrium high-density carrier system. ... Carrier spin and exciton optical orientation in semiconductors. ... Two-dimensional excitons in quantum wells and related quantum systems. €аState density in transverse magnetic field and effect of random potential fluctuation on one-particle spectrum shape. ...