2. Characteristics of ground-based observational data
2.1. Catalogue of faint stars
In the third decade of this century astronomers of the Pulkovo observatory proposed a programme for determination of absolute proper motions of stars using faint galaxies as an inertial reference frame (Deutsch 1952). The programme, called the Catalogue of Faint Stars (KSZ - abbreviated from Russian Katalog Slabykh Zvezd), required the collaboration of many observatories from the former Soviet Union, China, Rumania, and Spain. The project covers 306 () selected fields with galaxies on the whole sky, including 205 ones in declination zone from to .
The first epoch of photographic observations were obtained practically by all participating observatories. For the second epoch only Golosiiv (Kyiv) and Pulkovo observatories have completely finished the observations whereas the Moscow, Tashkent, and Shanghai observatories have almost finished them. Unfortunately, only episodic observations of the second epoch were carried out by the other KSZ programme participants. At present nearly 20 individual catalogues of absolute proper motions within the KSZ programme were compiled. The whole complex of catalogues consists of more than 80000 stars in KSZ fields.
Rather substantial investigations including the compilation of some individual and combined KSZ catalogues have been carried out at the Main Astronomical Observatory of National Academy of Sciences of Ukraine (Golosiiv Observatory) for many years. Some general catalogues were compiled here using available individual KSZ catalogues obtained at different observatories and published before 1987. These catalogues were applied to different astrometric studies and investigations of stellar astronomy problems (Kharchenko 1987, Rybka 1990). A description of some Golosiiv KSZ catalogues is given in Kharchenko et al. (1991).
A new version of the general catalogue, the so-called General compiled catalogue of absolute Proper Motions (GPM), will include nearly 60000 stars with magnitudes from 8 to 15.5 in 185 areas with 550 galaxies. At present, the first part of this catalogue (GPM1) has been completed for bright stars of the Hipparcos Input Catalogue (Rybka & Yatsenko 1996). The second part will contain all remaining stars with a limiting photographic magnitude 15.5. The GPM1 catalogue consists of absolute proper motions of 977 Hipparcos stars in 180 areas north of degrees of declination. Table 1 gives some characteristics of the KSZ catalogues used for the construction of the GPM1 catalogue.
Table 1. Some characteristics of KSZ catalogues
2.2. Programme for a complex study in the main meridional section of the galaxy
The main task of the programme for a complex study in the main Meridional section of the Galaxy (MEGA) is the investigation of kinematics and structure of the Galaxy (Einasto et al. 1987). The programme includes the construction of catalogues of proper motions of stars with respect to galaxies in selected fields of the sky along the main meridian of the Galaxy, their positions, stellar magnitudes in UBVR and Vilnyus systems, parameters of stellar classification: absolute stellar magnitudes, effective temperatures, metallicities of all stars to in 47 areas of the sky. Approximately one third of the KSZ fields being close to the main meridian of the Galaxy (within ) has been included in the MEGA programme.
Within the MEGA programme a general catalogue of absolute proper motions for 14111 stars with limiting magnitude of relative to 206 galaxies was obtained by Kharchenko (1987). The catalogue was compiled using observations with double astrograph () at Golosiiv observatory. The first epoch plates (with emulsions Kodak Oa-0, Agfa Astro, Ilford Zenith) have been taken by many astronomers in 1953-1962., the plates of the second epoch (ORWO ZU-21 emulsion) have been obtained by N.Kharchenko in 1981-1984. In addition, the AGK3 and SAO catalogues have been used for the compilation of the general catalogue. Table 2 lists all catalogues used in this compilation.
Table 2. Number of stars from different catalogues used in the MEGA general catalogue
Special methods developed at Golosiiv observatory including the selection of kinematically homogeneous group of reference stars, the removal of systematic errors in proper motions (especially magnitude equation), and the calibration of stellar magnitudes were applied to compile the general catalogue.
The mean square errors of proper motions in the GPM1 and MEGA general catalogues are on average.
© European Southern Observatory (ESO) 1997
Online publication: June 30, 1998