M31N 2025-02b is a Recurrence of the Newly-Identified Recurrent Nova M31N 2001-11a
ATel #17182; A. W. Shafter (SDSU), K. Hornoch (Ondrejov)
on 14 May 2025; 05:49 UT
Distributed as an Instant Email Notice Novae
Credential Certification: Allen W. Shafter (ashafter@sdsu.edu)
Subjects: Optical, Nova, Transient
A comparison of the position of M31N 2025-02b (AT2025axv), discovered on 2025 Feb. 05.471 by K. Itagaki, has revealed that it is spatially coincident within ~1.1 arcsec with the published position of a previously identified nova, M31N 2001-11a (ShA 67), reported by Alksnis et al. (2008, Astronomy Letters, 34, 563). A comparison of the published finding charts for the two novae confirms a spatial coincidence to of order one arcsec. The novae are located ~18' from the center of M31 (16.9' E and 5.9' N of the nucleus), making the probability of a chance positional coincidence of two unrelated novae of order only p ~ 0.0004. Finally, we note that the peak magnitude reported for M31N 2001-11a (B=17.1) agrees remarkably well with that observed for M31N 2025-02b (m=17.1, unfiltered). Taken together, the available evidence strongly supports the conclusion that the latter eruption is a recurrence of a newly-identified recurrent nova, M31N 2001-11a. This discovery makes M31N 2001-11a the 22nd known recurrent nova in the Andromeda galaxy.
