... Using a simple 2-D Gaussian Point Spread Function (PSF) on a constant (flat) sky background, I derive a theoretical photometric and astrometric performance model for analytical and digital PSF-fitting stellar photometry. ... The photometric performance is maximized when either the effective background area or the effective-background-level measurement error is minimized. ... An important, but frequently ignored, noise source is the uncertainty of the measurement of the effective background level ( )...

... Search . ATNF Home . About ATNF . ... About ATNF overview . ... Australia Telescope Steering Committee . ... Parkes radio telescope . ... Parkes | ... A Search for Bright Kuiper Belt Objects . ... Since 1992, 60 large Kuiper belt objects have been detected by ground-based telescopes. ... The detection of brighter objects would improve our ability to determine the Kuiper belt objects' surface composition and provide constraints on the population statistics of different formation mechanisms. ...

... In typical nightly use, the wide field and planetary telescope and cameras record images of favorably placed objects in the sky, including constellations, bright variable stars, nebulae through narrow-band filters, comets, the Moon, and planets. ... Shared Skies telescopes are available for use by students at the University of Louisville and the University of Southern Queensland, and by teachers and students in middle and high schools mentored by faculty at the universities. ...

... Dept. for Physics of Stars&Galaxies . ... Using a database view Sloan Digital Sky Survey (SDSS), containing almost a million spectra created 15,000 sample galaxies with active star formation, which is used for various studies and physical state of evolution of galaxies. ... Star clusters of the Galaxy . The project MWSC (Milky Way Star Clusters) directory using 2MASS, which includes nearly 500 million vision to the limit Ks = 15.3, analyzed more than 4,000 cluster-like objects in the galaxy. ...

... Director of the RAS ISR . RAS Academician . ... Astrophysics module Kvant of the orbital complex Mir launched in 1987 contains the largest on the station complex of the scientific equipment named the orbital observatory Roentgen. Observatory Roentgen consists of 4 X-ray telescopes, jointly exceeding the range of energies from 2 to 800 keV. ... Among the most significant results that were received in the observatory Roentgen are: . ... measurement of the periods of 9 X-ray pulsars; . ...

RADIOASTROPHYSICAL DEPARTMENT • INSTITUTE OF SOLAR-TERRESTRIAL PHYSICS RAS SB . ... SSRT - Possibilities of observing . ... Investigations of the SSRT 5.7 GHz radio maps in conjunction with images obtained in other emission ranges, suggested the following conclsions: . ... Solar images obtained in line H a ;(on the left, 16:11 UT, Big Bear observatory) and in the microwave emission (on the right, 04:04 UT, SSRT) 4 march 1997 . ...

New reduction of minor planets photographic plates obtained with Pulkovo Normal Astrograph A.A. Berezhnoy Pulkovo Observatory of RAS, Saint-Petersburg, Russia Minor Planet observations at Pulkovo Periodical observations of 14 bright asteroids named Selected Minor Planets (SMP) were performed at Pulkovo since 1948 within the international framework started by works of B.V. Numerov and D. Brouwer. ... 108 133 113 74 124 67 97 88 14 84 64 5 20 19 Epochs (YYYY.MM) 1200 Mean values of total obs. ...

On January 23, 1998 the space probe NEAR was on its way to its closest approach to Earth. Shortly before this, a so-called sunglint event was scheduled: by re-orienting its solar panels in order to reflect sunlight onto Earth's surface, the probe would shine for a few minutes brighter than any star in the sky. ... However, we were able to record a series of images of the space probe shortly before the sunglint event, and we have assembled them into a movie. ...

... 2009 March 3 . The Helix Nebula from La Silla Observatory . ... The Helix Nebula is one of brightest and closest examples of a planetary nebula , a gas cloud created at the end of the life of a Sun-like star. The outer gasses of the star expelled into space appear from our vantage point as if we are looking down a helix . ... A close-up of the inner edge of the Helix Nebula shows complex gas knots of unknown origin . ... About APOD | ... NASA Official: Phillip Newman Specific rights apply . ...

... A star was observed at different zenith distances during one night at the Engelgardt's Astronomical Observatory in the program of atmospheric extinction study at blue. ... The determination of the star's brightness was performed with the method of photon counting. ... Variable star. ... The brightness of the variable star was measured occasionally during the other nights, and moments of maximal values of brightness (15.59m) were received on nights 2­5, the 2nd table. ... JD 2452805. ...

The ESA/ESO Astronomy Exercise Series 2 . The Distance to Messier 100 as Determined by Cepheid Variable Stars . ... The small variations in distance to the individual Cepheid variable stars in the Cloud are negligible compared with the much larger distance to the SMC. ... In this way Cepheid variable stars can be used as one of the 'standard candles' in the Universe that act either as distance indicators themselves or can be used to calibrate (or set the zero point for) other distance indicators. ...

... The spectroscopic data were obtained with the 6m telescope of the Special Astrophysical Observatory of Russian Academy of Science (SAO RAS) during run in October 1999. ... The widths of the slit of 1.2 and 2 were used. ... Observations have been conducted mainly under the software package NICE in MIDAS, described by Kniazev & Shergin ([ 1995 ]). ... All primary data reduction was carried out in the standard way, similar to that described in Kniazev et al. ([ 2000b ]). ...

Contents. planet: 5 - Jupiter satellites: J1 - Io : 10, J3 - Ganymede : 15, J4 - Callisto : 6 total number: 31 type: relative dates: 1997-1997 observatory: see observatories list in the relevant article. ... Emelianov N. V., Vashkovjak S. N. (2009) Astrometric results of the observations of the mutual occultations and eclipses of the Galilean satellites of Jupiter in 1997. ... Position angle A in degrees (topocentric for mutual occultation or heliocentric for mutual eclipse) 10. ...

... This is a personal project collecting and documenting early images of Harvard College Observatory, focusing on the site at Observatory Hill (previously Summer House Hill). ... Annals of the Astronomical Observatory of Harvard College / History and Description of the Astronomical Observatory of Harvard College vol. ... Here's my understanding at this time. The precise timing of star transits on the meridian circle is used to determine the star's exact position at the meridan, and hence in the sky. ...

According to observations by NASA's Chandra X-ray Observatory and ground-based optical telescopes, the supernova SN 2006gy is the brightest and most energetic stellar explosion ever recorded and may be a long-sought new type of explosion. The bottom left panel is an infrared image, using adaptive optics at the Lick Observatory, of NGC 1260, the galaxy containing SN 2006gy. ... X ray: NASA/CXC/UC Berkeley/N.Smith et al.; Infrared: Lick/UC Berkeley/J.Bloom & C.Hansen ...

. The XMM-Newton website has moved to the following location: . http://www.cosmos.esa.int/web/xmm-newton

DIGITAL WDC EXCHANGE FORMAT . FOR OBSERVATORY 1.0 MINUTE VALUES 1. ... DATA-1 .. DATA-60 are 1-minute values of the given element for that hour. ... Typically, digital 1-minute values received by WDCs from organizations operating automatic magnetic observatory instruments are averages of more frequendy sampled values, e.g. 10-second point samples. ... If the method used to obtain 1-minute average values is important to a user, the WDC will assist in determining the exact procedure applied. ...

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. ...

... К И И ДЕ К И Й Й И ?Й К Abstract The modern observations of planetary nebulae (PNe) are used to create a new catalogue of element abundances for galactic and extragalactic PNe. Some of these abundances, esp ecially C ones, need to b e refined. ... К 18 7 6 5 4 3 2 1 0 16 14 Density (PDF) РЫЬК Й Й Й Й Density (PDF) 12 10 8 6 4 2 8.3 8.4 8.5 lg(N/H)+12 8.6 8.7 0 8.85 8.9 8.95 9 lg(O/H)+12 9.05 9.1 К ОК ЕИ Ц И МО И И И Д К Й ОМЙПМБК НМБИ Д К ОЕК К Й ПК Д И ? ...

GRANAT is the Russian x-ray sattelite launched to the high apogee orbit (200,000 km) and operated almost for 10 years (1989 -1999) , carrying out four major instruments: French SIGMA coded-mask hard x-ray telescope (30-1000 keV), Soviet ART-P coded-mask telescope (2??-60?? keV), all-sky monitor WATCH (6-150 keV), and a gamma-burst detector PHEBUS . ... Since September 1994, GRANAT is in the survey mode. ... Explore pages devoted to individual GRANAT instruments (including main scientific results): . ...