Independent Discovery of a Probable Nova in M31
ATel #17457; K. Hornoch (Ondrejov), H. Kucakova (Charles University), A. W. Shafter (SDSU)
on 27 Oct 2025; 20:34 UT
Distributed as an Instant Email Notice Novae
Credential Certification: Allen W. Shafter (ashafter@sdsu.edu)
Subjects: Optical, Nova, Transient
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 900-s R-band CCD frame taken on 2025 Oct. 26.861 UT with the 0.65-m telescope at Ondrejov.
The object was independently discovered on Oct. 26.555 UT by J. Xu et al. and designated as
AT 2025abrs.
The object was designated by us as M31N 2025-10c and is located at R.A. = 0h41m47s.59, Decl. = +41o16'22".0 (equinox 2000.0), which is 639.6" west and 13.5" 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) and the 0.45-m telescope at Opava (O45):
Date [UT] | Mag | Err | Filter | Telescope
2025-10-20.768 | >20.6 | | R | O45
2025-10-26.861 | 18.3 | 0.1 | 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
