The mass of the asteroid belt . ... The mass of the main asteroid belt is estimated as 13.5 10 -10 аЛ Sun . Hidden mass does not exceed two percent of this value. It is shown that almost all asteroids with absolute magnitude H < 14 have been found up to the distance 3.8 AU from the Sun. Estimations of the masses of different zones in the asteroid belt, including the Trojans, are obtained. ... asteroid belt, asteroid mass, absolute magnitude, taxonomical class. ...

... The Round Earth . ... Aristarchus around 270 BC derived the Moon's distance from the duration of a lunar eclipse (Hipparchus later found an independent method). ... Let R be the radius of that circle and T the time it takes the Moon to go around once, about one month. ... Viewed from Earth, a "new Moon" (occuring between the time a thin crescent is last seen before sunrise and the time one is seen shortly after sunset) happens when the Moon in its apparent motion around the sky overtakes the Sun. ...

Astrophysics 405 Homework Assignment 4 Tully­Fisher Galaxies in the Expanding Universe Due 1999 April 15 This assignment is a ``dry lab'' simulation of a galaxy observation project. ... Images, spectra, and apparent magnitudes mB for a collection of nearby galaxies have been provided. ... For those galaxies you are unable to classify, assume type Sc. (g) Compute the T­F distance for each galaxy. ... 2 Galaxy Data Use the following data in your calculations. There are 32 galaxies in this sample. ...

... Its apparent diameter of 18.0 arc minutes corresponds to a linear extension of about 180 light years; Kenneth Glyn Jones mentions an estimate of even 20 arc minutes from deep photographic plates, corresponding to about 200 light years linear diameter. It appears somewhat smaller in amateur instruments, perhaps about 10 minutes of arc. ... Red: 20x3 minute subs, totaling 1 hour . Green: 20x3 minute subs, totaling 1 hour . ... Copyright (c) Amateur Telescope Makers of Boston, Inc. ...

... We compare our results with the GRANAT X-ray observations of the Galactic center (Churazov et al. ... It is instructive to compare our results for the Galactic center starburst with what might be expected for a continuous star formation, with the average rate characteristic for the whole Galaxy. For this continuous star formation model, we would expect to observe in the region of around the Galactic center about 10% of the total number of X-ray sources in the Galaxy. ...

... The greater the distance, the smaller the parallax. ... That triangle has the same proportions as the much larger triangle ABC, and therefore, if the distance B'C to the thumb is 10 times the distance A'B' between the eyes, the distance AC to the far landmark is also 10 times the distance AB. ... The most distant objects our eyes can see are the stars, and they are very far indeed: light which moves at 300,000 kilometers (186,000 miles) per second, would take years, often many years, to reach them. ...

Astronomy Picture of the Day . ... 9.10.2012 . ... Credit Copyright: Rogelio Bernal Andreo (Deep Sky Colors) Explanation: It's easy to get lost following the intricate filaments in this detailed mosaic image of faint supernova remnant Simeis 147 (S147). ... The supernova remnant has an estimated age of about 40,000 years, meaning light from the massive stellar explosion first reached Earth 40,000 years ago. ... Publications with keywords: supernova remnant . ... Puppis A Supernova Remnant . ...

... 365­368, ISSN 1055-6796, Photo copying p ermitted by license only, c Cambridge Scientific Publishers Distance scale calibration from kinematic analysis of an ensemble of the galactic planetary nebulae V.V. Akimkin1, I.I. Nikiforov2, A.F. Kholtygin 1 2 2 Astronomical Institute of the Russian Academy of Sciences, Russia Sobolev Astronomical Institute of St. Petersburg State University, Russia Received 1 February, 2012 We study the kinematics of ensembles of planetary ...

COLOR PRINT OF NGC 4881 AND PART OF THE SURROUNDING FIELD This photo mosaic, which shows a field of distant galaxies, is a computer enhanced reproduction of a picture taken 4 March 1994 with the repaired Hubble Space Telescope. ... It is a 13th-magnitude elliptical galaxy in the outskirts of the Coma Cluster, a great cluster of galaxies more than 5 times farther away than the Virgo Cluster. ... We must find that peak ("turnover") in NGC 4881 in order to judge the distance. ...

User catalogs allow you enter positions for your objects into a file, to save time during an observing run. ... Before diving into the details, here is an example: # default coordinate system and object # (these are the standard defaults, so if you like them you can omit this line) CSys=FK5; Date =2000; RotType= Object ; RotAng=0 # some random objects # Name Pos1 (e.g. RA) Pos2 (e.g. Dec) Options in keyword-value format NGC6543 rot 90 ... Object Data . Defaults . Catalog Options . ...

Bizyaev D., "The Argument Against Long Extragagalactic Distance Scale", Astron. ... Soviet Astronomy) 1997. ... Zasov A., Bizyaev D., "An Estimate of the Hubble Constant using a Criterion for Gravitational Stability of Gaseous Discs", Pis'ma v Astron. ... 1996. ... D.Bizyaev, "Types of galaxies", 1996, Zvezdochet, No 11, p.22 (in Russian) . D.Bizyaev, "The Hubble Constant", 1996, Zvezdochet, No 2, p.20 (in Russian) . D.Bizyaev, "Magellanic Clouds", 1995, Zvezdochet, No 6, p.12. (in Russian) . ...

... Based on the brightest blue and red stars we estimate the following distances to the galaxies: 3.2 Mpc for UGCA 105, 2.6 Mpc for UGCA 86, 1.8 Mpc for UGCA 92, 1.7 Mpc for NGC 1569, and 1.7 Mpc for Cas 1. ... 1991), 1.8 Mpc for NGC 1569 and 2.2 Mpc for UGCA 92 (Karachentsev et al. ... Estimating distance moduli to NGC 1560 and UGCA 105 by the Tully-Fisher method, these authors obtained a distance of < D > = (3.6 ± 0.5) Mpc, and ascribed it to the rest of the galaxies in the group. ... 1994). ...

... In this paper we present the results of detailed B, V, R, I, and H study of the isolated nearby blue compact dwarf (BCD) galaxy NGC6789. Judging from the literature the observed galaxy has not been resolved into stars up to now. ... The distance of the galaxy, estimated from the tip of the red giant branch (TRGB) is 2.1 Mpc which places NGC6789 close to the Local Group. ... Key words: nearby galaxies: dwarf galaxies (NGC 6789): distance moduli: star content . ... Distance. ...

Next: NICMOS/HST H-band (F160W) Images Up: NICMOS Science Previous: HST NICMOS Observations of . ... Observations of P . ... The NICMOS team has devised a comprehensive program of observations of the Galactic Center. ... Data in hand give a first look at variability and a detailed look at the search for the tip of the main sequence will be discussed where NICMOS has demonstrated adequate sensitivity and photometric precision to identify likely O8-B1 stars at the Galactic Center. ...

... PUL2 catalog contains original absolute proper motions of 59646 stars in 149 fields with galaxies. ... Mean errors of relative proper motions in PUL2 catalog is 5.5 mas/year. ... The external mean error of one relative proper motion of a bright star of PUL2 catalog is 9 mas/year for both of coordinates. ... After issue of UCAC2 catalog, we decided to improve accuracy of proper motions, using Pul-3 coordinates (of 1950s) as the first epoch, and UCAC2 coordinates as the second epoch. ...

... Courtesy of NASA/ESA Observation data (J2000 epoch) Constellation Right ascension Declination Redshift Distance Type Serpens Caput 15h 17m 14.4s[] +21° 35 08[] 12,740±50 km/s[][1] 600±30 Mly (183±8 Mpc)[1] SA0(r) [citation needed ] [a] Apparent dimensions (V) 0.28 в 0.28[] Apparent magnitude (V) 16.0[] Notable features Ring galaxy Other designations PGC 54559,[] PRC D-51[] See also: Galaxy, List of galaxies Hoag's Object is a non-typical galaxy of the type known as a ring galaxy. ...

... First direct distance to Andromeda . ... F or the first time, an eclipsing binary has revealed the precise distance to the Andromeda Galaxy (M31), say astronomers in Spain, America, and Scotland. ... In the past, astronomers have determined M31's distance by observing its stars, notably its Cepheids and RR Lyraes, but deducing these stars' intrinsic brightnesses has depended on observations in other galaxies. ... Only registered members of Astronomy.com are allowed to comment on this article. ...

I/199 Lick Northern Proper Motion Program: NPM1 Catalog (Klemola+ 1987) =============================================================================== = Lick Northern Proper Motion Program: NPM1 Catalog Klemola A.R., Hanson R.B., Jones B.F. <Astron. ... Positions are given for equinox B1950 and computed epoch 1950. ... Other data given for each star are: the original mean epoch, a stellar class code, the number of NPM fields measured, and discrepancy flags for position, proper motion, and photometry. ...

... The Second International Astronomy Olympiad . ... Problems to solve, 8-10 Form Text of these problems is available in Russian too. ... Two stars have the same absolute magnitude. ... The orbital period of Mars is 687 days. ... See problem 2. for 8-10 Form. ... Problem to solve, 9-12 Form Text of the problem is available in Russian too. ... Problem is about Doppler-effect, to find velosities of two stars using their spectra and spectrum of our Sun, to estimate speed of the Earth moving around the Sun...

... THE SIMPLEST MODEL. ... 13, Moscow 119992, Russia E-mail: san@sai.msu.ru Abstract: The analysis of the simplest model shows that an asteroid ­ rubble pile evolves, depending on the parameter V2d (where V is the average velocity of fragments and d is the average distance between fragments), either as a conglomerate of "independent mutually gravitating clusters" (when V2d < fm, where f is the gravitational constant and m is the average mass of a fragment) or as a "receding cluster" (when V2d > fm). ...