Mira kinematics in the post-Hipparcos era

¹ Main Astronomical Observatory, Golosiiv, Kiev – 127 03680, Ukraine e-mail: nkhar@mao.kiev.ua
² Institute of Astronomy of the Russian Acad. Sci., 48 Pyatnitskaya St., Moscow 109017, Russia e-mail: lena@inasan.rssi.ru; malkov@inasan.rssi.ru
³ Astronomisches Rechen-Institut Heidelberg, Mönchhofstraße 12-14, 69120 Heidelberg, Germany

Corresponding author: E. Schilbach, elena@ari.uni-heidelberg.de

Received: 11 July 2000
Accepted: 19 December 2001

Abstract

The complete data set of Mira variables from the 4th edition of the General Catalog of Variable Stars was analyzed and supplemented by the proper motions and radial velocities presently available for Miras. The resulting sample of 724 Miras with periods between 78 and 612 days contains proper motions reduced to the Hipparcos system, radial velocities and V magnitudes. For each of 10 subgroups of Miras divided according to their periods and spectral types, statistical parallaxes were determined by application of five different methods. The mean absolute magnitudes, the spatial velocities and their dispersions as well as the elements of the Galactic orbits were computed as functions of the periods. The () relation obtained was found to be considerably steeper than the PLR usually assumed for LMC Miras. For Miras in the period range  days, no significant net motion radially outwards in the Galaxy as suggested by Feast & Whitelock (2000) was found. The predicted frequency of Miras was computed as a function of the visual magnitude.