Independent Discovery of an Apparent Nova in M31 and its Likely Identification with the Recurrent Nova M31N 1984-07a

ATel #15760; K. Hornoch, H. Kucakova (Astronomical Institute, Ondrejov, Czech Republic), R. Fidrich (HAA/VSS), A. W. Shafter, R. M. Quimby, A. Tedeschi, JT Markham-Adkison, C. Martin (SDSU), P. Zasche (Astronomical Institute, Charles U., Prague, Czech Republic), J. Zhao (Xingming Observatory) for the Popular Supernova Project (PSP) collaboration
on 13 Nov 2022; 21:33 UT
Distributed as an Instant Email Notice Novae
Credential Certification: Allen W. Shafter (ashafter@sdsu.edu)

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We report the independent discovery of an apparent nova in M31 on a co-added 810-s R-band CCD frame taken on 2022 Nov. 12.077 UT with the 0.65-m telescope at Ondrejov.

The object was independently discovered on Nov. 12.526 UT by M. Zhang et al. and designated as PNV J00424719+4116196 = AT 2022zyr, and by R. Fidrich on 12.066 UT (the earliest of the measurements reported thus far) both reported here.

The object was designated by us as M31N 2022-11b, and is located at R.A. = 0h42m47s.19, Decl. = +41o16'19".8 (equinox 2000.0), which is just 32.3" east and 11.3" north of the center of M31 (see link to discovery image below).

The nova appears to be another eruption of the known M31 recurrent nova M31N 1984-07a, but its close proximity to the nucleus of M31 makes confirmation difficult. We are currently attempting to do the precise astrometry necessary to confirm the recurrent nature of the current nova.

The following R-band magnitudes were obtained using the 0.65-m telescope at Ondrejov (OND) and the 1.0-m telescope at Mount Laguna Observatory (MLO):

 
  Date [UT]    |  Mag   | Err  | Filter  | Telescope> 
 
2022-11-10.953 | <19.5  |      | R       | OND 
2022-11-11.188 | <19.2  |      | R       | MLO 
2022-11-12.028 |  18.0  | 0.2  | R       | OND 
2022-11-12.077 |  17.2  | 0.15 | R       | OND 
2022-11-12.125 |  17.08 | 0.06 | R       | MLO 
2022-11-12.271 |  16.56 | 0.05 | R       | MLO 
2022-11-12.695 |  16.15 | 0.08 | R       | OND 
2022-11-12.708 |  16.13 | 0.07 | R       | OND 
 

A recent measurement r-band measurement (16.08±0.05), taken on Nov. 12.694 UT by Horti-David et al. (ATel #15759), confirms that we have caught the nova on the rise to maximum light.

As with all extragalactic novae, follow-up spectroscopic and photometric observations to confirm the nova's nature and determine its spectroscopic class and rate of decline (speed class) are encouraged.

Discovery image