... Once a star loses its disk, it appears to be free to spin--up. ... By the time a star reaches the 1 day periods seen in some stars in Orion OB1a and b it must have lost their disk a relatively long time ago, and have spent only 5% of their post--birthline, PMS lifetime with a disk. ... These stars are roughly 10 Myr old. ... The most rapid rotation period among the Orion OB1a stars is about 0.7 days, which means that such a star would have lost its disk at an age of no older than 250,000 years. ...

. Next: The lighthouse model Up: A Tutorial on Radio Previous: Early searches at other . љ . The lighthouse model . Periods and period derivatives . The structure of neutron stars . The magnetic fields of neutron stars . Radio pulse characteristics . Optical and other high energy emission . The interstellar medium . Galactic population . Jon Bell . Thu Dec 19 15:15:11 GMT 1996

. Pulkovo Observatory of Russian Academy of Sciences is situated . near Saint-Petersburg. It was founded in 1839. 196140, Saint-Petersburg, Pulkovskoye chaussee 65/1 . English version . Russian version . This page has been accessed times since May 1, 1999.

... Be Stars . ... Magnetic Stars . ... Magnetic fields in stars are common. ... The earliest star known to have a magnetic field is the O-star 1 Ori C, one of trapezium stars in the central cluster of the Orion nebula of spectral type O6. ... The non-existence of more rapidly rotating magnetic stars was thought to be an immediate consequence of the magnetic field: The field would help the star to get rid of angular momentum by forcing the wind into co-rotation, and so to brake down the star. ...

... Finally, we improve previous limits on the far-IR flux from the inner ~600 pc of NGC 1097 by an order of magnitude, providing a better estimate of the total bolometric emission arising from the active galactic nucleus and its associated central starburst. ... ADS ] . ADS Citation Query . citations = 27 . citations vs. year [year,citations] . 2010,3][2011,6][2012,7][2013,4][2014,4][2015,3] . Copyright 2012 Karl D. Gordon All Rights Reserved ...

Magnetic Stars, 2011, pp. ... We discuss a recent detection of a strong, organized magnetic field in the bright, broad­line B2V star, HR 5907, using the ESPaDOnS spectropolarimeter on the CFHT as part of the Magnetism in Massive Stars (MiMeS) survey. ... 2010; Rivinius et al., 2010). ... From our longitudinal magnetic field measurements, we confirm this period, which we adopt as the rotational period of this star (see Fig. 1), making it the fastest rotating, non­degenerate magnetic massive star! ...

Next: A Universal Diagram for Up: ``Ecology'' of Magnetic Rotators Previous: The Corotation Radius . The interaction of a magnetic rotator with the surrounding plasma to a large extent depends on the relation between the four characteristic radii: the stopping radius, , the gravitational capture radius,   , the light cylinder radius,   , and the corotation radius,   . ... Hence, the classification of the interaction regimes may well mean the classification of magnetic rotators. ...

... The Search of a pulsar Once the dedispersed time series is obtained, a Fourier transformation is performed. ... 2 Binary parameters The orbit of a pulsar , as well as any object, in a binary system is determined in its geometrical characteristics, space displacement and syncronised in time by the following parameters : Semimajor axis Eccentricity Longitude of periastron Binary period Time of ascending node a e PB T0 True spin period and observed spin period The ...

... Models of central engines (1) Potential of disk accretion onto stellar mass black holes: disk binding energy: thin disk life time: - accreted mass - disk outer radius - gravitational radius - Shakura­Sunyaev parameter Ultra-dense Hyper-Eddington neutrino cooled disks !! ... 1989); Neutron star + Neutron star Neutron star + Black hole White dwarf + Black hole Black hole + compact disk Burst duration: 0.1s ­ 1.0s Released binding energy: (1.2) Collapsars­ origin of long duration GRBs? ...

... Magnetic Storms . ... The Earth's own magnetic field is probably created in the Earth's core, believed to contain molten iron, by a "fluid dynamo" . ... Jupiter . ... The magnetospheres of the giant planets differ from the Earth's in at least four ways. ... If Jupiter's magnetosphere has the same proportions, the solar wind would need 2-3 days to cover the corresponding distance (equal to about half the Earth-Sun distance!), during which the planet might have rotated 5-7 times around its axis. ...

Pulsars; evolution of stellar magnetism JD L 07/05/09 Leverhulme Lectures on Stellar Magnetism Discovery of pulsars First pulsar discovered accidentally in radio study of scintillating (small angular diameter) radio sources ... Fields in more massive PMS stars could be due to protostar dynamos, or fossil remnants, or more complex processes.. ... Fields sometimes present in only one star of SB. ... And we have seen that neutron star fields may decay as fossils.. ...

Gamma Cas and Friends . ... 24.12.2009 . ... A hot, variable, and rapidly rotating star about 600 light-years distant, Gamma Cas also ionizes surrounding interstellar material , including the wispy IC 63 (left) and IC 59 emission and reflection nebulae. The two faint nebulae are physically close to Gamma Cas , separated from the star by only a few light-years. ... NASA Web Site Statements, Warnings, and Disclaimers . NASA Official: Jay Norris. ... A service of: LHEA at NASA / GSFC . ...

... Astrophysics Group . ... RAPID collaboration . ... SKA AAVS0 array . Beam measurement and calibration of the SKA AAVS0 array at Lord?s Bridge using a UAV system . ... First Science with SDSS-IV MaNGA . ... SKA Aperture Array in Australia . ... We are closely collaborating with MIT Haystack observatory to make early use of SKA technology БЂ“ low frequency aperture array elements, which have been designed here. ... It is an array of 50-100 small, low-gain broadband antennas operating below 500 MHz. ...

... The TRACE images may be used without restrictions in publications of any kind. ... These two images, taken on 18 November 2000 at 15:54UT and 16:11UT, respectively, show such an event: the red circle in the image to the left shows a region where many loops are cooling, with bright loop tops (the intensity scales with the square root of the image to reduce the dynamic range). ... See also a collection of images related to the Sun, other cool stars, and solar-terrestrial effects . ... Images | ...

... This class is designed to be an up to date summary of the last 10-20 years of observations relevant to Cosmology. ... Theory today is bombarded by a vast array of observational data but there remains no clear and preferred model for the origin and evolution of structure in the Universe. ... The inflationary paradigm and the nature of the Dark Matter - Inflation solves a lot of problems that are inherent in the standard Big Bang Model. ... Kinds of Dark Matter and Observational Constraints . ...

... The storm began quite unexpectedly. The strongest geomagnetic storm for the last seven months began on Earth almost precisely at the same time as the solar eclipse reached its maximal stage, the culmination of which occurred at GMT 02:35 (06:35 Moscow time). ... Oscillations of such amplitude in the magnetic field have not been observed since October, 11th of last year, which is more than seven months ago. ... We can only add that the magnetic storm lasted approximately 9 hours. ...

... The evolution of magnetic fields in OB-type stars from the study of open clusters of different ages . ... Wade G. A. The MiMeS Project: Magnetism in Massive Stars . ... Polosukhina N., Shavrina T., Drake N., Kudryavtsev D. Smirnova M. New results of the spectral observations of CPstars in the Li I 6708? spectral region with BTA telescope of SAO RAS . ... Magnetic Stars-2010 . ... List of participants . List of reports . ... Laboratory for the Stellar Magnetism Study of SAO of the RAS . ...

The Earth. ... The middle raiding of the Earth is 6371,032 km, the pole 6356,777 km equatorial - 6378,160 km. The Earth surface area is 510,2 mln km^2, 70,8% of which is the World ocean. ... According to the modern cosmogonical views the Earth was formed 4,6 - 4,7 billions years ago from the protoplanet cloud captured by the Sun. ... The Earth is conditionally divided into 3 parts: a bark a cloak and a core (in the centre). The external layer - the bark is 35 km thick. ... Above the Earth. ...

... Ciel Espace, le magazine qui vous guide toujours plus loin . ... des actualit†йs . ... des pages consacr†йes †а la publication de vos photos Mais c'est aussi une vraie communaut†й avec laquelle partager votre passion et nourrir votre curiosit†й. Accueil Des collisions de galaxies †а lтАЩorigine des premiers trous noirs . ... Les trous noirs supermassifs, ces monstres cosmiques, se sont peut-†кtre form†йs tr†иs t†‡t dans l'histoire de l'univers par collision de galaxies primordiales. ... Etat du ciel...

These images, taken by New Horizons Long Range Reconnaissance Imager (LORRI), show four different faces of Pluto as it rotates about its axis with a period of 6.4 days. All the images have been rotated to align Pluto's rotational axis with the vertical direction (up-down) on the figure, as depicted schematically in the upper left. From left to right, the images were taken when Pluto s central longitude was 17, 63, 130, and 243 degrees, respectively. ...