Independent Discovery of a Probable Nova in M81

ATel #15246; K. Hornoch, H. Kucakova (Ondrejov), S. C. Williams (Turku), G. Sala, J. Jose (UPC-IEEC), B. Stecklum (TLS), M. J. Darnley (LJMU), A. Kaur (PSU), D. H. Hartmann (Clemson), A. W. Shafter (SDSU)
on 27 Feb 2022; 19:33 UT
Credential Certification: Allen W. Shafter (ashafter@sdsu.edu)

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The M81 nova monitoring collaboration reports the independent discovery of a probable nova in M81 on a co-added 5400-s unfiltered CCD frame taken on 2022 Feb. 24.947 UT with the 0.65-m telescope at Ondrejov.

The object was independently discovered on Feb. 25.708 UT by M. Zhang and X. Gao and designated as AT 2022dgd. The object was designated by us as M81N 2022-02b and is located at R.A. = 9h55m13s.87, Decl. = +69o05'46".9 (equinox 2000.0), which is 103.4" west and 111.8" 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 
 
2022-02-23.192 | <22.0  |      | C       | OND 
2022-02-24.947 |  21.1  | 0.25 | C       | OND 
2022-02-25.899 |  20.2  | 0.15 | C       | OND 
2022-02-27.189 |  20.4  | 0.25 | 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 G2-3200 MkII CCD camera (with a Kodak KAF-3200ME sensor and standard BVRI photometric filters) mounted at the prime focus. The unfiltered OND photometry was calibrated against R-band comparison stars from Perelmuter & Racine (1995).

Discovery image