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arXiv · 2104.09865

Detection of an energetic flare from the M5V secondary star in the Polar MQ Dra

Gavin Ramsay·Pasi Hakala·Matt Wood
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Abstract

MQ Dra is a strongly magnetic Cataclysmic Variable whose white dwarf accretes material from its secondary star through a stellar wind at a low rate. TESS observations were made of MQ Dra in four sectors in Cycle 2 and show a short duration, high energy flare (~10^35 erg) which has a profile characteristic of a flare from the M5V secondary star. This is one of the few occasions where an energetic flare has been seen from a Polar. We find no evidence that the flare caused a change in the light curve following the event and consider whether a coronal mass ejection was associated with the flare. We compare the frequency of energetic flares from the secondary star in MQ Dra with M dwarf stars and discuss the overall flare rate of stars with rotation periods shorter than 0.2 d and how such fast rotators can generate magnetic fields with low differential rotation rates.

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Gavin Ramsay, Pasi Hakala, Matt Wood. 2021-04-20. Detection of an energetic flare from the M5V secondary star in the Polar MQ Dra. https://doi.org/10.1093/mnras/stab1140

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