2006/02/01 by V. D’Orazi, V. D'Orazi, A. Bragaglia +3
Physics and Astronomy · #Apparent magnitude #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Astrophysics and Star Formation Studies #Cluster (spacecraft) #Diagram #Field (mathematics) #Hertzsprung–Russell diagram #Magnitude (astronomy) #Metallicity #Open cluster #Physics #Radial velocity #Red clump #Stars #Statistics #Stellar evolution #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1111/j.1365-2966.2006.10118.x
published as Mon.Not.Roy.Astron.Soc. 368 (2006) 471-478 · MNRAS, in press. Degraded resolution for Fig. 4
arxiv created 2006/02/01 · openalex publication_date 2006/03/09 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We have obtained medium- and low-resolution spectroscopy and BVI CCD imaging of Berkeley 32, an old open cluster which lies in the anticentre direction. From the radial velocities of 48 stars in the cluster direction, we found that 31 of them, in crucial evolutionary phases, are probable cluster members, with an average radial velocity of +106.7 (σ= 8.5) km s−1. From isochrone fitting to the colour–magnitude diagrams of Berkeley 32, we have obtained an age of 6.3 Gyr, (m−M)0= 12.48 and E(B−V) = 0.10. The best fit is obtained with Z= 0.008. A consistent distance, (m−M)0≃ 12.6 ± 0.1, has been derived from the mean magnitude of red clump stars with confirmed membership; we may assume (m−M)0≃ 12.55 ± 0.1. The colour–magnitude diagram of the nearby field observed to check for field stars contamination looks intriguingly similar to that of the Canis Major overdensity.