Contributed Talk - Splinter HotStars

Thursday, 15 September 2022, 14:45   (SFG 1030 / virtual HotStars)

Stellar multiplicity studies of B stars using multiple observation methods and radial velocity analysis

Lukas Stock, Andreas Schrimpf
Philipps-Universit├Ąt Marburg

High mass stars, especially B type stars, are great test objects for stellar evolution models. To confirm the models we need to know whether the B star has companions or even exoplanets. In 2021 the first exoplanet surrounding a binary star with a total mass of more than 10 solar masses was found. Most binary stars are found using the radial velocity (RV) method. However, B type stars are no easy target for the RV method as their spectra show very few, broad lines. We present a way to determine radial velocity of B stars up to roughly 100 m/s accuracy using cross-correlation analysis of high resolution spectra. Also photometric, astrometric and spectroscopic surveys as BRITE, GAIA, LAMOST, SDSS, RAVE or the upcoming Vera Rubin Observatory deliver many data to determine changes of the stars properties over time. We want to combine different methods, including own time dependent spectroscopic measurements with a Shelyak eShel spectrometer, to better determine the stellar parameters of these hot stars. Combining these methods will allow making estimates about stellar winds, age and radial pulsations of the stars surface. We will also show ways to improve the accuracy of the Shelyak eShel spectrograph, which is a relatively cheap echelle spectrograph and therefore a possible investment even for smaller working groups.