/ftp/cats/I/208



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I/208     The 90000 stars Supplement to the PPM Catalogue     (Roeser+, 1994)
The following files can be converted to FITS (extension .fit .fit.Z .fgz)
	ppm3
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Query from: http://vizier.cds.unistra.fr/viz-bin/VizieR?-source=I/208
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drwxr-xr-x 317 cats archive 8192 Feb 28 11:16 [Up] drwxr-xr-x 2 cats archive 289 Jan 12 2023 [TAR file] -rw-r--r-- 1 cats archive 453 Dec 19 2022 .message -r--r--r-- 1 cats archive 9529 Jun 30 2004 ReadMe -rw-r--r-- 1 cats archive 2629 Oct 25 2007 +footg5.gif -rw-r--r-- 1 cats archive 28076 Mar 5 2008 +footg8.gif -r--r--r-- 1 cats archive 14491 May 18 1994 desc.txt -r--r--r-- 1 cats archive 2545733 May 18 1994 ppm3.dat.gz [txt] [txt.gz] [fits] [fits.gz] [html]
Beginning of ReadMe : I/208 The 90000 stars Supplement to the PPM Catalogue (Roeser+, 1994) ================================================================================ The 90000 stars Supplement to the PPM Star Catalogue Roeser S., Bastian U., Kuzmin A. <Astron. Astrophys. Suppl. Ser. 105, 301 (1994)> =1994A&AS..105..301R (SIMBAD/NED BibCode) ================================================================================ ADC_Keywords: Positional data ; Proper motions Description: Since its appearance in 1966, the SAO Catalogue (SAO, 1966) has been the primary source for stellar positions and proper motions. Typical values for the rms errors are 1 arcsec in the positions at epoch 1990, and 1.5 arcsec/century in the proper motions. The corresponding figures for the AGK3 (Heckmann et al., 1975) on the northern hemisphere are 0.45 arcsec and 0.9 arcsec/century. Common to both catalogues is the fact that proper motions area derived from two observational epochs only. Both catalogues are nominally on the B1950/FK4 coordinate system. The PPM Star Catalogue (Roeser and Bastian, 1991, Bastian et al., 1993; for a short description see Roeser and Bastian, 1993) effectively replaced these catalogues by providing more precise astrometric data for more stars on the J2000/FK5 coordinate system. Compared to the SAO Catalogue the improvement in precision is about a factor of 3 on the northern and a factor of 6 to 10 on the southern hemisphere. In addition, the number of stars is increased by about 50 percent. Typical values for the rms errors on the northern hemisphere are 0.27 arcsec in the positions at epoch 1990, and 0.42 arcsec/century in the proper motions. On the southern hemisphere PPM is much better, the corresponding figures being 0.11 arcsec and 0.30 arcsec/century. The improvement over the SAO Catalogue was made possible by the advent of new big catalogues of position measurements and by the inclusion of the century-old Astrographic Catalogue (AC) into the derivation of proper motions (for a description of AC see Eichhorn, 1974). But even PPM does not fully exploit the treasure of photographic position measurements available in the astronomical literature of the last 100 years. The Astrographic Catalogue contains roughly four million stars that are not included in PPM. For most of them no precise modern-epoch position measurements exist. Thus it is not yet possible to derive proper motions with PPM quality for all AC stars. But among the 4 million there is a subset of some 100,000 CPC-2 stars that are not included in PPM. These stars constitute the 90,000 Stars Supplement to PPM. See file "desc.txt" for complete explanations provided by the authors.