... The HST uses an onboard model of its orbit to perform in real-time various control functions relating to spacecraft operations and observation support. ... New coefficients for the ephemeris are updated every other day, and are archived as FITS keywords for each HST observation data set. Using these coefficients,an observer can perform a variety of calibration and characterization calculations relating to the orbital position and velocity of the telescope. ...

Three different forms are possible for representing Results of calculation of spherical coordinates: . the form designated as EMP is similar to that used in the Ephemerides of Minor Planets, having formal precision of 0.01 minute of time in right ascension and 0.1 minute of arc in declination. Longitude, latitude, azimuth and altitude are also displayed with comparable formal precision. the form designated as Positions has enhanced formal precision. ...

ON THE IMPACT OF THE GALACTIC ABERRATION ON VLBI-DERIVED PRECESSION MODEL Z.M. MALKIN Pulkovo Observatory Pulkovskoe Ch. ... Corrections to adopted precession rate are usually computed from the linear trends in long-term time series of celestial pole offset (CPO), which are the differences between the measured and the theoretical coordinates of the celestial pole. ... CONCLUSIONS We have estimated the impact of GA on parameters of precession-nutation model derived from VLBI observations. ...

Contents] [Prev page] [Next page] [Index] . ... Positioning HTML Content Using Styles . Positioning HTML Content Using the <LAYER> Tag . ... Absolute Positioning . ... Creating Positioned Blocks of Content Dynamically . Writing Content in Positioned Blocks . ... Positioning the Flower Layers . Positioning and Moving the Fish and Poles . Defining the onLoad Handler for the BODY Element . ... Adding Another Layer to Contain the Reverse Fish Image . ... The Initialization Functions . ...

. Computer Ephemeris. Lunar equatorial positions. Explanations. Each row contains at 0 h and 12 h of Time Dynamical Terrestrial: month, day, apparent right ascension (hours, minutes, seconds), apparent declination (degrees, minutes, seconds of arc) and geocentric distance (in Earth's radii).

... After all we cannot send a probe to the star Altair to confirm that it is 17 light years away. ... The "Bessel determined that the star 61 Cygni was about ten light years away" Earth goes around the Sun in one year, so in six month it is in the opposite position in its orbit. ... In 1838 Bessel determined that the star 61 Cygni had a parallax of 0.314 arcseconds and therefore the star was about ten light years away (today the distance is more precisely measured to be 11.4 light years). ...

... The described algorithm is suitable for measurements of complex images of stars. ... a) the zero-based number of stars in the complex (multicentric) image, . b) set of preliminary coordinates - x i , y i , for all stars, index i is number of a star, . ... i - index of a star in the complex image; . ... These parameters are calculated by a nonlinear method of a least squares.The main output parameters of this algorithm are x i , y i ; where the index i is number of a star in the multicentric image. ...

... Space flight . ... Baikonur . ... Space camp . Space Hotel . ... On May 5, 1957 acceptance act of the first launch complex was signed, and as early as on May 6, 1957 the first "R-7" missile was erected on the site. The cosmodrome consists of nine launch complexes with fourteen launchers, thirty-four engineering complexes, three fuelling stations for space vehicles and two aerodromes. ... Services / Baikonur: General description Technical description Shedule of launches Photo gallery Price . ...

... FIELD | ... static int . ... Field Detail static final int AREA . ... Constant Field Values . static final int MEAN . ... static final int STD_DEV . ... static final int MODE . ... static final int MIN_MAX . ... static final int CENTROID . ... static final int CENTER_OF_MASS . ... static final int PERIMETER . ... static final int LIMIT . ... static final int RECT . ... static final int LABELS . ... static final int ELLIPSE . ... static final int INVERT_Y . ... static final int CIRCULARITY . ...

Multichannel Flare Spectrograph . ... phi - the angle between the green vertical line passing through the solar disk image and the violet radius vector "r" of the object located at the center of the spectrograph slit- red cross. positive - clockwise, negative - counterclockwise . ... mx = x coordinate of the coelostat main mirror . ... x : carthesian solar coordinate alog axis parallel to solar equator (in arcsec) . y : carthesian solar coordinate alog axis parallel to solar axis (in arcsec) ...

... Tonight's Sky . ... Search By Name Enter coordinates Use current location . ... Observing . ... Astronomy for Kids . ... Observing springtime deep-sky objects with a large telescope . ... How do astronomers use Cepheid variables to measure distances? ... Get instant access to subscriber content on Astronomy.com! ... If you are already registered on Astronomy.com, please log in below. ... Receive news, sky-event information, observing tips, and more from Astronomy's weekly email newsletter. ...

... We have compared visualized fields of GSC and USNO A1.0 catalog with unpublished photographic finding charts that were sent by L. Plaut to the compilers of the GCVS. ... 7-15 A9 --- GCVS GCVS or NSV name 17-25 F9.4 --- GSC GSC number 26 A1 --- NoteFlag *Nonstar (GSC) flag 28-29 I2 h RA2000GSC.h Hours RA (GSC), equinox 2000.0 31-32 I2 min RA2000GSC.m Minutes RA (GSC), equinox 2000.0 34-38 F5.2 s RA2000GSC.s Seconds RA (GSC), equinox 2000.0 40 A1 --- DE2000GSC.- ... Plaut, L., 1966, Bull. ...

Microsymposium 38, MS083, 2003 (A4 format) MERCURY: LOCAL VARIATIONS OF THE PHOTOMETRIC RELIEF. ... Because of trajectory and pointing angle constraints the planet could be observed from Mariner 10 only over a small range of phase angles between about 75o and 110o. Therefore the photometric investigations are restricted to measuring the distribution of brightness on the Mercurian disk. ... Raw versions of real-time processing pictures FDS 0000984 and FDS 0000986 were used (images 196 and 202). ...

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 | ...

... The overall globular cluster population is divided by gap in the metallicity function at [Fe/H]=-1.0 into two discrete groups with well-defined maxima at [Fe/H]=-1.60?0.03 dex, and -0.60?0.04 dex. ... Clusters with extremely blue horizontal branches occupy a spherical volume of radius ~ 9 kpc, have high rotational velocities ( V rot =77?33 km/s), have substantial and equal negative radial and vertical metallicity gradients, and are, on average, the oldest group (the old-halo subsystem). ...

This WWW form allows the user to list selected portions of the NRAO/VLA Sky Survey (NVSS) radio source catalog. ... Until the completion of the survey the source catalog will NOT cover the entire region of the survey and care must be exercised in interpreting the results of a catalog search. ... The second parameter in the "Search radius" box or one of the optional items in a position list can be used to specify a region in which to look for other sources. ... An example of a position list entry is: . ...

... Bad Astronomy . ... Mad Science . ... Keep Bad Astronomy close to your heart, and help make me filthy rich. ... The name "parsec" is indeed a distance of 3.26 light years. ... First off, we need to know about "parallax". ... A great example is easy to show: hold a thumb up in front of your face, about 20 centimeters away. ... That angle is called the parallax angle, and it depends on two things: how far apart your eyes are (the baseline ), and how far away your thumb is. ... 2008 Phil Plait. ...

... Up: Description of program searchdup Previous: Program use . Input records are ordered per date of observation, and the list of known (observed) sources is cleared. Each record is compared in position to all the known sources. If the sky distance is less or equal to the specified one, the record is added to the list of observations for that source. If no known sources are within the specified radius, a new source is created, with the coordinates of the observation record. ...

... 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). ...