Probing the origin of stellar flares on M dwarfs using TESS data sectors 1-3
Abstract
Detailed studies of the Sun have shown that sunspots and solar flares are closely correlated. Photometric data from Kepler/K2 has allowed similar studies to be carried out on other stars. Here, we utilize Transiting Exoplanet Survey Satellite (TESS) photometric 2-min cadence of 167 low-mass stars from Sectors 1 to 3 to investigate the relationship between star-spots and stellar flares. From our sample, 90 per cent show clear rotational modulation likely due to the presence of a large, dominant star-spot and we use this to determine a rotational period for each star. Additionally, each low-mass star shows one or more flares in its light curve and using Gaia Data Release 2 parallaxes and SkyMapper magnitudes we can estimate the energy of the flares in the TESS band-pass. Overall, we have 1834 flares from the 167 low-mass stars with energies from 6.0 × 1029 to 2.4 × 1035 erg. We find none of the stars in our sample show any preference for rotational phase, suggesting the lack of a correlation between the large, dominant star-spot, and flare number. We discuss this finding in greater detail and present further scenarios to account for the origin of flares on these low-mass stars.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- October 2019
- DOI:
- 10.1093/mnras/stz2205
- arXiv:
- arXiv:1908.02698
- Bibcode:
- 2019MNRAS.489..437D
- Keywords:
-
- stars: activity;
- stars: flare;
- stars: low-mass;
- stars: magnetic fields;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 10 pages, 9 figures, 2 tables, accepted for publication in MNRAS