2004/05/07 by Z. Kadla, Kadla, Z.
Physics and Astronomy · #Astrophysics (astro-ph) #FOS: Physical sciences #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/0405137
11 pages, 8 figures
arxiv created 2004/05/07 · arxiv updated 2013/11/18
An analysis of available Galactic globular cluster data on metallicity, ages, the distribution of stars on the horizontal branch and the distribution of the periods of RR0 Lyr variables showed that: 1. The latter two characteristics can be used for determining the Oosterhoff type. 2. The metallicities of the observed OoI and OoII clusters overlap in a narrow interval -1.65<[Fe/H]<1.52. 3. The OoII clusters are characterized by R-B<0, a statistically significant relation (r=0.97) between the relative number of B(BS) and V(VS) stars on the horizontal branch. 4. The OoI clusters divide into two groups: R-B<0 and R-B>0 with a relation between B and R (r=0.90). The former clusters do not show a relation between VS and RS stars and the latter a relation between VS and BS stars on the horizontal branch. 5. The oldest clusters are characterized by BS close to 1 and the youngest by R close to 1.