Recurrent Novae in M31

Abstract

The reported positions of 964 suspected nova eruptions in M31 recorded through the end of calendar year 2013 have been compared in order to identify recurrent nova candidates. To pass the initial screen and qualify as a recurrent nova candidate two or more eruptions were required to be coincident within 0.1 , although this criterion was relaxed to 0.15 for novae discovered on early photographic patrols. A total of 118 eruptions from 51 potential recurrent nova systems satisfied the screening criterion. To determine what fraction of these novae are indeed recurrent the original plates and published images of the relevant eruptions have been carefully compared. This procedure has resulted in the elimination of 27 of the 51 progenitor candidates (61 eruptions) from further consideration as recurrent novae, with another 8 systems (17 eruptions) deemed unlikely to be recurrent. Of the remaining 16 systems, 12 candidates (32 eruptions) were judged to be recurrent novae, with an additional 4 systems (8 eruptions) being possibly recurrent. It is estimated that ∼4% of the nova eruptions seen in M31 over the past century are associated with recurrent novae. A Monte Carlo analysis shows that the discovery efficiency for recurrent novae may be as low as 10%

A remarkable recurrent nova in M 31: The predicted 2014 outburst in X-rays withSwift

“…For our large neighbour galaxy M 31, Shafter et al (2015) recently reported a comprehensive archival study revealing 16 A&A 580, A46 (2015) likely RNe among the almost one thousand known outbursts (see the online catalogue 1 of Pietsch et al 2007). In X-rays, Henze et al (2014e, hereafter HPH2014) presented updated results from a dedicated monitoring survey of M 31 novae which, together with the archival analysis of Pietsch et al (2005Pietsch et al ( , 2007, resulted in an unprecedentedly large sample of 79 novae with SSS counterpart (see also Henze et al 2010Henze et al , 2011.…”

M31N 2008-12a—THE REMARKABLE RECURRENT NOVA IN M31: PANCHROMATIC OBSERVATIONS OF THE 2015 ERUPTION

“…But it is the nearby Andromeda Galaxy (M 31), with an annual nova rate of -+ 65 15 16 yr −1 (Darnley et al 2006), that provides the leading laboratory for the study of galaxy-wide nova populations (see, for example, Ciardullo et al 1987Ciardullo et al , 1990aShafter & Irby 2001;Darnley et al 2004Darnley et al , 2006Henze et al 2008Henze et al , 2010Henze et al , 2011Henze et al , 2014bShafter et al 2011aShafter et al , 2011bShafter et al , 2015aWilliams et al 2014Williams et al , 2016. Since the discovery of the first M 31 nova by Ritchey (1917, also spectroscopically confirmed) and the pioneering work of Hubble (1929), more than 1000 nova candidates have been discovered (see Pietsch et al 2007;Pietsch 2010, and their on-line database 46 ), with over 100 now spectroscopically confirmed (see, for example, Shafter et al 2011b).…”

“…However, the range of methodologies employed predicted a wide range of contributions, from 9%-38%, with the authors themselves indicating that the statistical errors are likely to be "much too small" (Pagnotta & Schaefer 2014). Shafter et al (2015a) uncovered multiple eruptions of 16 RN systems in M 31. The subsequent analysis predicted a historic M 31 RN discovery efficiency of just 10% and that as many as 33% of M 31 nova eruptions may arise from RN systems (  P 100 rec years).…”

Multifrequency Behaviour of Galactic and Extragalactic Novae

“…Recurrent novae have an high rate of mass transfer that explains the short interval between outbursts [94]. Recurrent novae are possible progenitors for type Ia supernovae [146], [134].…”