Abstract Details
| Name: R Anusha Affiliation: Masters Student in Physics Conference ID: ASI2018_1645 Title : ULTRAVIOLET STUDIES OF CLASSICAL Be STARS Authors and Co-Authors : Vaishnavi R (Christ University), Paul KT(Christ University), Annapurni Subramaniam(Indian Institute of Astrophysics), Blesson Mathew(Christ University). Abstract Type : Poster Abstract Category : Stars,ISM and the Galaxy Abstract : Classical Be stars are B-type stars in the main sequence that exhibit line emission over the photospheric spectrum attributed with a circumstellar gaseous disk. This disc formation is commonly known as the Be phenomenon, is one of the unsolved problems in Be stars. One of the possible solutions can be due to optically invisible companion (Porter and Rivinius, 2003). Population models predict that 20% of Be stars can have White Dwarf (WD) companions whereas 60% can host Helium Sub-Dwarf (sdO). Only a few detections of WD companions to Be stars are confirmed. Henceforth we propose a method of detecting such invisible companions by means of Ultraviolet excess in Spectral Energy Distribution (SED) of such stars. For this study we used a sample of 150 Be stars from Mathew et. al (2010). We obtained UV data from GALEX and found that 82 have UV detections. Further, optical/IR magnitudes of these stars were compiled from archive which was used to construct SED. We quantified UV excess by fitting the SED with appropriate stellar atmospheres corresponding to spectral type of the Be star. The UV excess detected in such fashion is indicative of hot companion such as WD or sdO. This analysis can be followed up with UV observations of Be stars using Ultra Violet Imaging Telescope (UVIT) onboard ASTROSAT. |