Revealing the Binarity of HD 36030 -- One of the Hottest Flare Stars

Abstract

The Kepler and TESS space missions significantly expanded our knowledge of what types of stars display flaring activity by recording a vast amount of super-flares from solar-like stars, as well as detecting flares from hotter stars of A-F spectral types. Currently, we know that flaring occurs in the stars as hot as B-type ones. However, the structures of atmospheres of hot B-A stars crucially differ from the ones of late types, and thus the occurrence of flaring in B-A type stars requires some extension of our theoretical views of flare formation and therefore a detailed study of individual objects. Here we present the results of our spectral and photometric study of HD 36030, which is a B9 V star with flares detected by the TESS satellite. The spectra we acquired suggest that the star is in a binary system with a low-mass secondary component, but the light curve lacks any signs of periodic variability related to orbital motion or surface magnetic fields. Because of that, we argue that the flares originate due to magnetic interaction between the components of the system.

16 pages, 10 figures, 3 tables

References in corpus (18)

• The Transiting Exoplanet Survey Satellite
• A Grid of NLTE Line-Blanketed Model Atmospheres of Early B-type Stars
• Improving PARSEC models for very low mass stars
• Age determination for 269 $Gaia$ DR2 Open Clusters
• A selection of hot subluminous stars in the GALEX survey II. Subdwarf atmospheric parameters
• Gaia Data Release 3: The Galaxy in your preferred colours. Synthetic photometry from Gaia low-resolution spectra
• Stellar flares observed in long cadence data from the Kepler mission
• EvryFlare III: Temperature Evolution and Habitability Impacts of Dozens of Superflares Observed Simultaneously by Evryscope and TESS
• Rotational modulation in TESS B stars
• The Classificiation of Kepler B star Variables
• Do A-type stars flare?
• The unpopular Package: a Data-driven Approach to De-trend TESS Full Frame Image Light Curves
• Ondr}ejov echelle spectrograph, ground based support facility for exoplanet missions
• The IACOB spectroscopic database of Northern Galactic OB stars
• The IACOB spectroscopic database: recent updates and first data release
• Flares on A-type stars: Evidence for heating of solar corona by nanoflares?
• How long can LBVs sleep? A long-term photometric vaiability and spectral study of the Galactic candidate luminous blue variable MN112
• Flare stars in nearby Galactic open clusters based on {\it TESS} data

Cited by in corpus (1)

• Flares hunting in hot subdwarf and white dwarf stars from Cycles 1-5 of TESS photometry