Abstract Details

Name: Sindhu N
Affiliation: VIT University
Conference ID: ASI2017_1240
Title : How hot are Blue Stragglers?
Authors and Co-Authors : Annapurni Subramaniam (Indian Institute of Astrophysics, Bangalore), C Anu Radha(VIT University, Vellore)
Abstract Type : Oral
Abstract Category : Stars,ISM and the Galaxy
Abstract : The Ultraviolet (UV) studies are crucial in understanding the hotter stellar populations in star clusters. Blue stragglers (BSS) are stars in the clusters which are not well understood since it flouts the standard evolutionary tracks. Previous studies of the BSS have shown that they emit a significant flux in the UV domain (Landsman et al .1998). We analyse the BSS in two old open clusters; M67 and NGC 188. BSS are the brightest and hotter than the main sequence stars in the UV colour-magnitude diagram (CMD). The UV CMDs of two open clusters are constructed using far-UV (FUV) and near –UV (NUV) photometry of Galaxy evolution explorer (GALEX) GR6/GR7 archival data. From the analysis of UV CMD of the clusters, it is observed that BSS dominate flux in both FUV and NUV bands. 24 BSS of NGC 188 and 17 BSS of M67 are detected in GALEX. We estimate the effective temperature of all BSS by constructing the Spectral energy distribution (SED) using VOSED tool and probe for possible binary companions of BSS.