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Pulkovo compilation of radial velocities for 35495 stars in a common system.
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| Improved Astrometry and Photometry for the Luyten Catalog. II. Faint Stars and the Revised Catalog
We complete construction of a catalog containing improved astrometry andnew optical/infrared photometry for the vast majority of NLTT starslying in the overlap of regions covered by POSS I and by the secondincremental Two Micron All Sky Survey (2MASS) release, approximately 44%of the sky. The epoch 2000 positions are typically accurate to 130 mas,the proper motions to 5.5 mas yr-1, and the V-J colors to0.25 mag. Relative proper motions of binary components are measured to 3mas yr-1. The false-identification rate is ~1% for11<~V<~18 and substantially less at brighter magnitudes. Theseimprovements permit the construction of a reduced proper-motion diagramthat, for the first time, allows one to classify NLTT stars intomain-sequence (MS) stars, subdwarfs (SDs), and white dwarfs (WDs). We inturn use this diagram to analyze the properties of both our catalog andthe NLTT catalog on which it is based. In sharp contrast to popularbelief, we find that NLTT incompleteness in the plane is almostcompletely concentrated in MS stars, and that SDs and WDs are detectedalmost uniformly over the sky δ>-33deg. Our catalogwill therefore provide a powerful tool to probe these populationsstatistically, as well as to reliably identify individual SDs and WDs.
| Reliability of the HIPPARCOS Input Catalogue tested by the 'First look'
The reliability of the Input Catalogue is one of the keys for thesuccess of the Hipparcos mission. As the Input Catalogue is a catalogmade of very heterogeneous sources, many systematic reliability testswere conducted to eliminate errors on identifications, position,magnitude, etc. In March 1991, half of the Input Catalogue had alreadybeen checked by the 'First look' facility developed by the FASTconsortium at Utrecht. It is shown that less than 0.1 per cent of the118,000 stars of the observing program will not be detected.
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Группы:
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Наблюдательные данные и астрометрия
| Созвездие: | Гидра |
| Прямое восхождение: | 13h43m01.46s |
| Склонение: | -24°13'39.2" |
| Видимая звёздная величина: | 9.572 |
| Собственное движение RA: | 190.7 |
| Собственное движение Dec: | 37.7 |
| B-T magnitude: | 10.553 |
| V-T magnitude: | 9.653 |
Каталоги и обозначения:
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