M31N 2008-12a - The Remarkable Recurrent Nova in M31

Abstract

M31N 2008-12a is a remarkable recurrent nova within the Andromeda Galaxy. With eleven eruptions now identified, including eight in the past eight years, the system exhibits a recurrence period of one year, and possibly just six months. This short inter eruption period is driven by the combination of a high mass white dwarf ($1.38{\mathrm{M}}_{\odot }$) and high mass accretion rate ($\sim 1.6\times 10^{-7}{\mathrm{M}}_{\odot }{\mathrm{yr}}^{-1}$). Such a high accretion rate appears to be provided by the stellar wind of a red giant companion. Deep H$\alpha$ observations have revealed the presence of a vastly extended nebula around the system, which could be the `super-remnant' of many thousands of past eruptions. With a prediction of the white dwarf reaching the Chandrasekhar mass in less than a mega-year, M31N 2008-12a has become the leading pre-explosion type Ia supernova candidate. The 2016 eruption - to be the twelfth detected eruption - is expected imminently, and a vast array of follow-up observations are already planned.

6 pages, 1 figure, to appear in the proceedings of the 20th European Workshop on White Dwarfs (EuroWD16) held July 25-29th, 2016 at the University of Warwick, United Kingdom

Cited by in corpus (1)

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