A Close Pair of Distinct M81 Probable Novae PNV J09553921+6902382 and PNV J09553917+6902390
ATel #17154; K. Hornoch (Ondrejov), A. W. Shafter (SDSU), H. Kucakova (Charles University)
on 19 Apr 2025; 19:27 UT
Credential Certification: Allen W. Shafter (ashafter@sdsu.edu)
Subjects: Optical, Nova, Transient
In ATel #17131 we published discovery of a probable nova in M81 designated as PNV J09553921+6902382 and located at R.A. = 9h55m39s.21, Decl. = +69o02'38".2 (equinox 2000.0). After the discovery we searched known M81 nova candidates for possible previous eruptions of the current probable nova. We found one promising candidate discovered as a probable nova by K. Hornoch and H. Kucakova on 2013 Mar. 16.787 UT designated as PNV J09553917+6902390 and located at R.A. = 9h55m39s.17, Decl. = +69o02'39".0 (equinox 2000.0). The coordinates of the two probable novae differ by only 0.8", which is slightly more than is common position uncertainty. To be sure that the two observed eruptions do not originate from the same progenitor system, we precisely aligned images of the two objects. We used a co-added 3900-s unfiltered CCD image of the PNV J09553921+6902382 combined from two frames (to get better S/N) taken with the 0.65-m telescope at Ondrejov on 2025 Apr. 4.134 and 5.126 UT and a co-added 2000-s H-alpha image of the PNV J09553917+6902390 taken with the 2.5-m Isaac Newton Telescope + WFC at La Palma on 2013 Apr. 5.946 UT (see ATel #4968).
The result is seen in an aligned image
Although very close, it is apparent that the two objects are not, in fact, spatially coincident and thus they are two distinct probable novae.
