Independent Discovery of a Probable Nova in M81, M81N 2026-10a

ATel #18107; K. Hornoch, H. Kucakova (Ondrejov), A. W. Shafter (SDSU)
on 16 Oct 2026; 19:23 UT
Distributed as an Instant Email Notice Novae
Credential Certification: Allen W. Shafter (ashafter@sdsu.edu)

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We report the discovery of a probable nova in M81 on a co-added 3180-s unfiltered CMOS frame taken on 2026 Oct. 15.165 UT with the 0.65-m telescope at Ondrejov under cloudy conditions.

The object was independently discovered on Oct. 14.893 UT by Z. Mai et al.

The object has been designated by us as M81N 2026-10a and is located at R.A. = 9h56m00s.71, Decl. = +69o06'14".4 (equinox 2000.0), which is 147.5" east and 139.3" north of the center of M81 (see link to discovery image below).

Here we list the observing dates and corresponding photometry:

 
  Date [UT]    |  Mag   | Err  | Filter  | Telescope 
 
2026-09-28.093 | >21.3  |      | C       | OND 
2026-10-15.165 |  19.2  | 0.1  | C       | OND 
 

As with all extragalactic novae, follow-up spectroscopic and photometric observations to determine the nova's spectroscopic class and rate of decline (speed class) are encouraged. The OND 0.65-m is a reflecting telescope at the Ondrejov observatory operated jointly by the Astronomical Institute of ASCR and the Astronomical Institute of the Charles University of Prague, Czech Republic. It uses a Moravian Instruments C3-61000EC PRO CMOS camera (with a SONY IMX455 sensor and VRIH_alpha photometric filters) mounted at the prime focus. The unfiltered OND photometry was calibrated against R-band comparison stars from Perelmuter & Racine (1995).

Discovery image