Discovery of a Probable Nova in M81
ATel #17011; K. Hornoch (Ondrejov), A. W. Shafter (SDSU)
on 2 Feb 2025; 21:00 UT
Distributed as an Instant Email Notice Novae
Credential Certification: Allen W. Shafter (ashafter@sdsu.edu)
Subjects: Optical, Nova, Transient
We report the discovery of a probable nova in M81 on a co-added 3000-s unfiltered CCD frame taken on 2025 Feb. 1.765 UT with the 0.65-m telescope at Ondrejov. The new object is faintly visible also on a prediscovery co-added CCD frame taken on Jan. 29.746 UT with the same instrumentation.
The object designated PNV J09550507+6909090 is located at R.A. = 9h55m05s.07, Decl. = +69o09'09".0 (equinox 2000.0), which is 150.3" west and 313.9" 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
2025-01-26.834 | >21.8 | | C | OND
2025-01-29.746 | 20.4 | 0.3 | C | OND
2025-02-01.765 | 19.8 | 0.15 | 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