Informace o publikaci

Analysis of photometric and spectroscopic variability of red supergiant Betelgeuse

Autoři	JADLOVSKÝ Daniel KRTIČKA Jiří PAUNZEN Ernst ŠTEFL Vladimír
Rok publikování	2023
Druh	Článek v odborném periodiku
Časopis / Zdroj	New Astronomy
Fakulta / Pracoviště MU	Přírodovědecká fakulta
Citace
www	https://arxiv.org/pdf/2211.04380.pdf https://www.sciencedirect.com/science/article/pii/S1384107622001440
Doi	http://dx.doi.org/10.1016/j.newast.2022.101962
Klíčová slova	Betelgeuse; Red supergiants; Radial velocity; Photometry; Spectroscopy; Stellar pulsations
Popis	Betelgeuse is a pulsating red supergiant whose brightness is semi periodically variable and in February 2020 reached a historical minimum, the Great Dimming. The aims of this study are to characterize Betelgeuse’s variability based on available archival data and to study possible causes of light variability. Many spectra, from ultraviolet and optical regions, were evaluated for spectral analysis. The spectra were used primarily to determine radial velocities from different layers of atmosphere and their long-term evolution. Additionally, photometric data were analysed in different filters as well, to construct light curves and to determine periods of the variability. Spectroscopic and photometric variability are compared to each other and given into a context with the Great Dimming. The two most dominant photometric periods are P1=2190±270d and P2=417±17d, while the dominant optical (photospheric) radial velocity periods are P1,vr=2510±440d and P2,vr=415±11d. During the same time, the radial velocity determined from ultraviolet spectra also shows variability and is distinctively different from the variability of photospheric velocity, undergoing longer periods of variability. We attribute these velocities to the velocities at the base of outflowing wind. We also report a maximum of stellar wind velocity during the Great Dimming, accompanied by the previously reported minimum of brightness and the maximum of photospheric radial velocity. After the Dimming, Betelgeuse’s mode of variability has fundamentally changed and is now instead following a shorter period of ~200d.