Investigating the rotational phase of stellar flares on M dwarfs using K2 short cadence data

Doyle, Lauren, Ramsay, Gavin, Doyle, John Gerard, Wu, Kinwah and Scullion, Eamon (2018) Investigating the rotational phase of stellar flares on M dwarfs using K2 short cadence data. Monthly Notices of the Royal Astronomical Society, 480 (2). pp. 2153-2164. ISSN 0035-8711

[img]
Preview
Text
Scullion et al - Investigating the rotational phase of stellar flares on M dwarfs using K2 short cadence data AAM.pdf - Published Version

Download (836kB) | Preview
Official URL: https://doi.org/10.1093/mnras/sty1963

Abstract

We present an analysis of K2 short cadence data of 34 M dwarfs which have spectral types in the range M0-L1. Of these stars, 31 showed flares with a duration between ˜10 and 90min. Using distances obtained from Gaia DR2 parallaxes, we determined the energy of the flares to be in the range ˜1.2 × 10^29-6 × 10^34 erg. In agreement with previous studies we find rapidly rotating stars tend to show more flares, with evidence for a decline in activity in stars with rotation periods longer than ˜10 d. The rotational modulation seen in M dwarf stars is widely considered to result from a starspot which rotates in and out of view. Flux minimum is therefore the rotation phase where we view the main starspot close to the stellar disc centre. Surprisingly, having determined the rotational phase of each flare in our study we find none show any preference for rotational phase. We outline three scenarios which could account for this unexpected finding. The relationship between rotation phase and flare rate will be explored further using data from wide surveys such as NGTS and TESS.

Item Type: Article
Uncontrolled Keywords: stars: activity, stars: flare, stars: low-mass, stars: magnetic field
Subjects: F500 Astronomy
Department: Faculties > Engineering and Environment > Mathematics, Physics and Electrical Engineering
Related URLs:
Depositing User: Paul Burns
Date Deposited: 10 Oct 2018 10:47
Last Modified: 11 Oct 2019 08:25
URI: http://nrl.northumbria.ac.uk/id/eprint/36206

Actions (login required)

View Item View Item

Downloads

Downloads per month over past year

View more statistics