منابع مشابه
Cleaning the USNO-B Catalog through automatic detection of optical artifacts
The USNO-B Catalog of astrometric standards contains spurious entries that are caused by diffraction spikes and circular reflection halos around bright stars in the original imaging data. These spurious entries appear in the Catalog as if they were real stars; they are confusing for some scientific tasks. The spurious entries can be identified by simple computer vision techniques because they p...
متن کاملCompleteness of USNO-B for High Proper-Motion Stars
I test the completeness of USNO-B detections of high proper-motion (μ > 180mas yr) stars and the accuracy of its measurements by comparing them to the revised NLTT (rNLTT) catalog of Salim & Gould. For 14.5 < V < 18.5, only 6% of such stars are missing from USNO-B while another 4% have large errors, mostly too large to be useful. Including both classes, incompleteness is 10%. These fractions ri...
متن کاملStudy of USNO photographic plates of the Galilean satellites
About 500 photographic plates of the Galilean satellites made with the 26-inch refractor of USNO in Washington DC from 1967 to 1998 were digitized and reduced using the UCAC2 star catalog. Results on the ephemerides of the Galilean satellites and on the determination of the mass of Amalthea will be presented. An evaluation of the accuracy of several ephemerides of Jupiter on the 1967-1998 perio...
متن کاملPreliminary Results from the Usno Atomic Fountain Development Project
Atomic fountain clocks are emerging as an important new technology for the realization of extremely precise passive atomic standards. The U.S. Naval Observatory (USNO) has undertaken a project to develop atomic fountains for eventual incorporation into the USNO Master Clock. We have recently demonstrated short-term stability of ZxIO-” at I second with white frequency behavior into the mid I0,’5...
متن کاملAstrometric quality of the USNO CCD Astrograph (UCA)
The USNO 8–inch astrograph has been equipped with a Kodak 1536x1024 pixel CCD since June 1995, operating in a 570–650 nm bandpass. With 3–minute exposures well exposed images are obtained in the magnitude range R ≈ 8.5 − 13.5. An astrometric precision of 10 to 15 mas for those stars is estimated from frame–to–frame comparisons. External comparisons reveal an accuracy of about 15 mas for those s...
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ژورنال
عنوان ژورنال: The Astronomical Journal
سال: 2003
ISSN: 0004-6256,1538-3881
DOI: 10.1086/345888