New Insight into the FS CMa System MWC 645 from Near-Infrared and Optical Spectroscopy

0574032 - ASÚ 2024 RIV CH eng J - Článek v odborném periodiku
Torres, A.F. - Arias, M.L. - Kraus, Michaela - Mercanti, L. V. - Eenmae, T.
New Insight into the FS CMa System MWC 645 from Near-Infrared and Optical Spectroscopy.
Galaxies. Roč. 11, č. 3 (2023), č. článku 72. E-ISSN 2075-4434
Grant CEP: GA ČR(CZ) GA20-00150S
GRANT EU: European Commission(XE) 823734 - POEMS
Institucionální podpora: RVO:67985815
Klíčová slova: stars * emission-line * Be stars
Obor OECD: Astronomy (including astrophysics,space science)
Impakt faktor: 2.5, rok: 2022
Způsob publikování: Open access

We aim to contribute to the knowledge of a recently confirmed binary, MWC645, which could be undergoing an active mass-transfer process. We present near-infrared and optical spectra, identify atomic and molecular spectral features, and derive different quantitative properties of line profiles. Based on publicly available photometric data, we search for periodicity in the light curve and model the spectral energy distribution. We have detected molecular bands of CO in absorption at 1.62 mu m and 2.3 mu m for the first time. We derive an upper limit for the effective temperature of the cool binary component. We found a correlation between the enhancement of the H alpha emission and the decrease in optical brightness that could be associated with mass-ejection events or an increase in mass loss. We outline the global properties of the envelope, possibly responsible for brightness variations due to a variable extinction, and briefly speculate on different possible scenarios.
Trvalý link: https://hdl.handle.net/11104/0344393