Paolo Padovani , II Universit di Roma , Paolo Giommi , ASI, SDC and Fabrizio Fiore, ASI, SDC and Osservatorio Astronomico di Roma . Original Version: MNRAS, (1997), 284, 569 . Text copyright (c) 1997. ... We study the X-ray spectra of 114 flat-spectrum radio quasars (FSRQ) using the hardness ratios as given in the WGA catalogue of ROSAT sources. ... We find that FSRQ have a distribution of energy spectral indices ranging between 0 and 3 with a mean value alpha_x ~ 1. ... Figure 1 (13kb) . ...

... AstroCC is a coordinate conversion utility for astronomy. It accepts an object designation or the coordinates of an object and calculates coordinates in alternative systems, and at different dates, times, and locations. It also provides lunar and bright planet coordinates to aid in planning observations. ... BJD values may also be retrieved from http://astroutils.astronomy.ohio-state.edu/time/utc2bjd.html which is based on Eastman et al. ... Coordinate data are obtained from SIMBAD. ...

. ATMOSPHERIC INFLUENCE ON THE DIFFERENT RADIO-ENGINEERING . SYSTEM FUNCTIONING . The calculations of the atmospheric impact on terrestrial and satellite communication links with frequencies above 10 GHz using the ITU-R data bank. The correction of the Earth cover optical images obtained from the satellite/ . The Earth atmospheric influence on the radiowave propagation parameters in wide frequency range (from SLF to UV). Contact e-mail: . Pozhidayev Victor, Ph.D - vic@cplire.ru . © IRE RAS 1996-20 11

The silicates that produce the 10 and 18 micron features appear to be broadly similar to terrestrial minerals such as Forsterite and Enstatite. ... Where pre-solar silicate dust grains can be isolated from meteorite material, these also tend to be Mg-rich silicates rather than Fe-rich silicates. ... It has been suggested that the interstellar silicate grains have a different 10 micron feature profile than what is observed for the silicates around evolved stars. ...

. Chairs . Teachers . Postgraduate Students . Undergraduate Students . Courses . Head: A.M.Cherepaschuk . Vice-Head: A.C.Rastorguev . Webmaster: Yuri V. Pakhomov . pakhomov@sai.msu.su

Teaching courses . for student of the Department of Astrophysics and Stellar Astronomy . ... Geophysics and physics of the planets (Kurt, Panteleev) . ... Close Binary Stars . ... Solar Physics . ... This is introductory course for students of the third year of education which are familiar with elementary astronomy and general physics. ... The one-year course includes theory of radiation transfer, theory of internal stellar structure with account of binary systems with compact comapnions. ...

Databases (NSDC) of the Natural Planetary Satellites. ... NSDC: Database of astrometric observations of Natural Planetary Satellites . ... They are thoroughly looking for observations in different sources, creating their owndatabases which are then mostly inaccessible to other researchers. ... In the file "content" with explications, the reference is given to the data source as well as the bibliographic reference. ... Data sources. ... Why a specific bibliographic database for Natural satellites? ...

... sin f = y / r . cos f = x / r . ... They are now viewed as new definitions of the sine and cosine, for the polar angle f given by x and y ( a slightly different way of formulating this definition is described further below ). ... sin 2 f + cos 2 f = 1 . ... Angle . ... Many trigonometry texts define the sine and cosine slightly differently, using the so-called unit circle . ... Then the distance AB ("the sine line") equals sin a , and the distance OA ("the cosine line") equals cos a . ...

. " The Arecibo Observatory is sponsored by the National Science Foundation. Any opinions, findings and conclusions or recommendations . expressed in this publication are those of the author(s) and do not necessarily reflect the views of the National Science Foundation."

... Description . Catalog . ... In the Catalog, we publish equatorial (ЮБ 2000 , ЮД 2000 ) and galactic (l,b) coordinates of cluster centers derived as the position of overdensity in 2MASS catalog (Koposov et al. ... Distances, color-excesses and ages are the mean-square values calculated using all available evaluations from different color-magnitude diagrams. ... There are individual pages for every cluster where all available plots and parameters are published. ... 2002). ...

... ATNF Home . ... About ATNF overview . ... Australia Telescope Steering Committee . ... Australia Telescope User Committee . ... Astrophysics graduate student programs . ... Facilities . ATNF facilities . ... Australian Square Kilometre Array Pathfinder . Murchison Radio-astronomy Observatory . ... Parkes radio telescope . Australia Telescope Compact Array . ... Visiting Parkes radio telescope . Visiting Australia Telescope Compact Array . ... Parkes radio telescope webcam . ...

SAI VO . ... SAI CAS . ... Access . ... We present the results of the development of Sternberg Astronomical Institute Catalog Access Services (SAI CAS) project - the first and the only project in Russia, which provides online access to the major astronomical catalogues and different services on top of them. ... SAI CAS is an open-source implementation of the general Catalogue access service (influenced by SDSS CAS CASjobs project), based on original algorithms and open-source software. ... SAI MSU | ...

... Contact A Problem of an estimation of accuracy of the asteroid CCD observations . The Minor Planet Center supported by the Interntional Astronomical Union is the main office for keeping observational data of the small Solar System bodies and their investigations. ... At Pulkovo Observatory we are estimating an accuracy of the CCD asteroid observations obtained by amateurs and professional astronomers all over the World using the MPC database. ...

... Solar Data: f.e. X-ray . Night Sky Live . ... Heavens-Above: Sky chart, Satellites, Iridiums and astronomical objects For Moscow For SAO Baksan . ... ESO-MIDAS page . ... Tutorials for Astronomy . ... Asteroid and Comet Hazard . ... Observable Comets: This page lists links to orbital elements and ephemerides of (potentially) observable comets. ... Leonid page - a lot of information for years Comets and Meteor Showers . The American Meteor Society . ... North American Meteor Network Home Page . ...

Microsymposium 40, abstract 78, 2004 (A4 format) A TREATMENT OF DATA BANK OF MORPHOLOGIC CATALOGUE OF MERCURIAN CRATERS. ... Coordinates of craters in the catalogue are changed in accordance with [2] new data of Mercury"s North Pole. A treatment of data bank is fulfilled with the use of software in regime of "client-server" on the choice of ensemble of the objects, compiling maps of density distribution of craters. ... Flat floor of craters on Mercury is met often than on the Moon. ...

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Download Izmccd (~2.7 MB). ... a) a choice of the best mode of measurements of stars and objects ("Properties/Measurement"), . b) a choice of reference stars. ... 1) necessity of presence on an image of a plenty of stars (we recommend to apply this mode, if on the frame of reference stars is more 100) . ... Sx and Sy depend from residuals at all reference stars (reference stars are marked by blue color). ... These residuals are the image of the star a minus function of a profile for each pixel. ...

... Does the time it takes different methods to create all the elements coincide with the universeт??s accepted age? ... Illinois Urbana-Champaign) Different kinds of stars create elements at different rates, all of which are consistent with the age of the universe. Get instant access to subscriber content on Astronomy.com! ... Registration is FREE and takes only a few seconds to complete. If you are already registered on Astronomy.com, please log in below. ...

lsst.coordConv љ unknown . ... Classes . ... All љ Classes љ Namespaces љ Files љ Functions љ Variables љ Typedefs љ Enumerations љ Enumerator љ Pages . coordConv: Astronomical Coordinate Conversions . The coordConv package provides the following classes and functions. ... Coord : represents a position on the sky, with proper motion and radial velocity; provides easy access to spherical and cartesian position. ... Position conversion functions: . ... Time conversion functions: . ...

Astronomy Terms - To Help You Study The Universe . Articles | ... Learning about the universe, or the study of astronomy, can be fun for the individual or for the whole family. ... Learning a few simple terms will help you with this fascinating study. ... You will use a telescope or binoculars for your observation of the sky at night. ... Celestial Terms . ... Meteor or a shooting star – the light caused when a meteoroid burns up in Earth's . ... www.astronomy.net . About Astronomy Net | ...