机译:PPM-Extended (PPMX) - a catalogue of positions and proper motions
Univ Heidelberg, Zentrum Astron, Astron Rech Inst, D-69120 Heidelberg, Germany;
Ukrainian Acad Sci, Main Astron Observ, UA-03680 Kiev, Ukraine;
Astrophys Inst Potsdam, D-14482 Potsdam, GermanyRussian Acad Sci, Inst Astron, Moscow 109017, Russia;
catalogs; astrometry; GUIDE-STAR-CATALOG; HIPPARCOS CATALOG; TYCHO-2 CATALOG; 2MASS;