Independent Discovery of a Probable Nova in M31 and a Prediscovery Detection of PNV J00424614+4112388 = AT 2025kiq

ATel #17199; K. Hornoch (Ondrejov), H. Kucakova (Charles University), A. W. Shafter (SDSU)
on 21 May 2025; 19:30 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 a probable nova found during our survey of the central region of M31. The object was discovered on a co-added 990-s R-band CCD frame taken on 2025 May 21.028 UT with the 0.65-m telescope.

The object was independently discovered on May 20.153 UT by Z. Mai et al. and designated as PNV J00422300+4116197 = AT 2025kvc.

The object was designated by us as M31N 2025-05d and is located at R.A. = 0h42m22s.99, Decl. = +41o16'19".5 (equinox 2000.0), which is 240.5" west and 11.0" north of the center of M31 (see link to discovery image below).

The following R-band magnitudes were obtained using the 0.65-m telescope at Ondrejov (D65):

 
  Date [UT]    |  Mag   | Err  | Filter  | Telescope 
 
2025-05-14.074 | >19.7  |      | R       | D65 
2025-05-21.028 |  17.3  | 0.1  | R       | D65 
2025-05-21.070 |  17.4  | 0.1  | R       | D65 
 

We also report several prediscovery detections of PNV J00424614+4112388 = AT 2025kiq discovered by J. Zhao et al. on 2025 May 11.160 UT. We detected this probable very slowly evolving Jitter class nova first on Mar. 20.779 UT. The following prediscovery R-band magnitudes were obtained using the 0.65-m telescope at Ondrejov (D65):

 
  Date [UT]    |  Mag   | Err  | Filter  | Telescope 
 
2025-03-04.767 | >20.0  |      | R       | D65 
2025-03-09.771 | >19.9  |      | R       | D65 
2025-03-18.777 | >19.8  |      | R       | D65 
2025-03-20.779 |  19.0  | 0.25 | R       | D65 
2025-03-27.795 |  17.8  | 0.2  | R       | D65 
2025-04-21.109 |  18.8  | 0.25 | R       | D65 
2025-04-30.086 |  18.8  | 0.2  | R       | D65 
2025-05-07.087 |  17.9  | 0.2  | R       | D65 
2025-05-09.089 |  18.5  | 0.2  | R       | D65 
2025-05-10.098 |  17.9  | 0.2  | R       | D65 
 

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