The optical gravitational lensing experiment. Variable stars in globular clusters^*,**

III. RR Lyrae stars and Pop. II Cepheids in ω Centauri

¹ Warsaw University Observatory, Al. Ujazdowskie  4, 00-478 Warsaw, Poland
² Carnegie Observatories, Las Campanas Observatory, Casilla 601, La Serena, Chile
³ Department of Astronomy, University of Michigan, 821 Dennison Bldg., Ann Arbor, MI 48109-1090, U.S.A.

Send offprint request to: J. Kaluzny

Received: 3 January 1997
Accepted: 6 January 1997

Abstract

We present V-band photometry for 141 variable stars from the field of ω Cen. All but one variables are either RR Lyr stars or Pop. II Cepheids. One object is a distant background RR Lyr star from the galactic halo. The presented sample includes 33 newly identified variables, mostly low amplitude RR Lyr stars. We identified also two Pop. II Cepheids with exceptionally low amplitudes of light variations . The presented data may be used to study period changes of ω Cen variables and/or for Fourier decomposition of light curves.