| Popis: |
The distribution of the RR Lyrae stars in the globular cluster ω Centauri is studied, using the data published by Martin in 1938. Comparing the accumulated numbers of variables within the angular distance, r, from the centre of the cluster, it is shown that the known RRc variables seem to be less concentrated towards the centre than the RRab stars. 6-10 RRc stars are missing within r = 2–3 arcmin, if the two distributions are actually identical, as expected from evolution models. We conclude that the central region may contain several RRc stars that have not yet been discovered. This could be due to their relatively low amplitude, since it is very difficult to find low-amplitude variables by means of photographic photometry in the crowded, central region of ω Cen with large and varying corrections due to unresolved background light. |
