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PPM-Extended (PPMX) ? a catalogue of positions and proper motions
PPM-Extended (PPMX) ? a catalogue of positions and proper motions
- Source :
- Astronomy and Astrophysics; September 2008, Vol. 488 Issue: 1 p401-408, 8p
- Publication Year :
- 2008
-
Abstract
- Aims. We build a catalogue PPM-Extended?(PPMX) on the ICRS system which is complete down to a well-defined limiting magnitude and contains the best presently available proper motions suited for kinematic studies in the Galaxy.Methods. We perform a rigorous weighted least-squares adjustment of individual observations, spread over more than a century, to determine mean positions and proper motions. The stellar content of PPMX is taken from GSC?1.2 supplemented by catalogues like ARIHIP, PPM and Tycho-2 at the bright end. All observations have been weighted according to their individual accuracy. The catalogue has been screened towards rejecting false entries in the various source catalogues.Results. PPM-Extended (PPMX) is a catalogue of 18?088?919?stars containing astrometric and photometric information. Its limiting magnitude is about 15.2 in the GSC photometric system. PPMX consists of three parts: a) a survey complete down to RU= 12.8 in the magnitude system of UCAC2; b) additional stars of high-precision proper motions, and c) all other stars from GSC?1.2 identified in 2MASS. The typical accuracy of the proper motions is 2 mas/y for 66?percent of the survey stars (a) and the high-precision stars?(b), and about 10?mas/y for all other stars. PPMX contains photometric information from ASCC-2.5 and 2MASS.
Details
- Language :
- English
- ISSN :
- 00046361 and 14320746
- Volume :
- 488
- Issue :
- 1
- Database :
- Supplemental Index
- Journal :
- Astronomy and Astrophysics
- Publication Type :
- Periodical
- Accession number :
- ejs15821555