UVIT/AstroSat Investigation of a Low-luminous Blue Straggler Star in NGC 362: Detection of an Extremely Low-mass White Dwarf as Companion
Abstract
In the present study, we identified an extremely low-mass white dwarf as a companion to a low luminous blue straggler star within the Galactic globular cluster NGC 362. To conduct the analysis, we utilized data obtained from various sources, including AstroSat's Ultra Violet Imaging Telescope, UVOT, and the 2.2 m ESO telescope. By examining the spectral energy distribution of the blue straggler star candidate, we successfully identified an extremely low-mass white dwarf as its binary companion. We determined the effective temperature, radius, and luminosity for both, the extremely low-mass white dwarf and the blue straggler star candidate. Specifically, the extremely low-mass white dwarf exhibits an effective temperature of 15000 K, a radius of 0.17 R⊙, a luminosity of 1.40 L⊙, and a mass range of 0.19-0.20 M⊙. Furthermore, the position of the straggler star within the cluster suggests their formation via the Case A/B mass-transfer mechanism in a low-density environment.
- Publication:
-
Bulletin de la Societe Royale des Sciences de Liege
- Pub Date:
- June 2024
- DOI:
- 10.25518/0037-9565.11687
- arXiv:
- arXiv:2308.13602
- Bibcode:
- 2024BSRSL..93..300D
- Keywords:
-
- Stars: blue straggler;
- Hertzsprung-Russell and CM diagrams;
- Globular star clusters: individual: NGC362;
- Astrophysics - Solar and Stellar Astrophysics;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- 6 pages, 2 figures, Submitted: 31 May, 2023 and Accepted: 26 July 2023