M31N 2006-11c appears to be spatially coincident with PNV J00413317+4110124 and hence a recurrent nova in M31
ATel #7116; K. Hornoch (Astronomical Institute, Ondrejov, Czech Republic), A. W. Shafter (SDSU)
on 20 Feb 2015; 17:20 UT
Credential Certification: Allen W. Shafter (firstname.lastname@example.org)
Subjects: Optical, Nova, Transient
PNV J00413317+4110124 was recently identified as an apparent nova in M31 (ATel #7113). A subsequent comparison of its position with those of the nearly 1000 historical M31 nova candidates in W. Pietsch's catalog (http://www.mpe.mpg.de/~m31novae/opt/m31/M31_table.html) reveals that PNV J00413317+4110124 is located just 0.7" from the cataloged position of M31N 2006-11c, a nova discovered by K. Hornoch, M. Wolf, and P. Zasche on 2006 November 30.808 UT. A lightcurve of M31N 2006-11c (although with sparse coverage) puts the nova undoubtedly into the class of very fast novae. Its t_2 parameter cannot be derived accurately, but is likely in the range of 3-7 days.
A careful comparison of the finding charts for the two novae shows that they are spatially coincident to within their seeing disks. Based on a nominal separation of 0.7", the probability of a chance positional near coincidence of two unrelated novae at this position in M31 is only ~0.0012 (from equation 1 in Shafter et al. 2015, ApJS, 216, 34). We therefore conclude that M31N 2006-11c is likely a recurrent nova in M31, with PNV J00413317+4110124 representing the second recorded eruption of this system, occurring ~8.2 yr after the first.
We encourage spectroscopic observations of PNV J00413317+4110124 in order to confirm the nature of the object and to determine its spectroscopic class.