H-alpha detection of recent novae AT 2023brc, AT 2022abzg and AT 2023ax in M31
ATel #15926; A. Valcheva (Sofia University, Bulgaria), M. Minev (IA and NAO, BAS, Bulgaria), E. Ovcharov, P. Nedialkov (Sofia University, Bulgaria)
on 3 Mar 2023; 21:33 UT
Credential Certification: Antoniya Valcheva (valcheva@phys.uni-sofia.bg)
Subjects: Optical, Nova, Transient
We report detected H-alpha emission from three recent novae in M31 - AT2023brc (XM96MZ, PNV J00422147+4112452, M31N 2023-02a), AT2022abzg (XM90MZ, PNV J00423788+4112491, M31N 2022-09b) and AT2023ax (XM94MZ, PNV J00430924+4117022, ZTF23aaaairl).
Our observations in narrowband H-alpha (FWHM of 3 nm) were performed with the FoReRo2 focal reducer at 2m RCC telescope at NAO Rozhen, Bulgaria. H-alpha magnitudes were obtained from 5x300 sec co-added images. R-band photometry (5x120 sec co-added images) is also available. The photometric information is summarized below:
| 2023 Feb. 22.7443 UT | 2023 Feb. 22.7594 UT
#Object | H-alpha mag | R mag
AT2023brc | 15.54±0.02 | 18.22±0.03
AT2022abzg | 14.91±0.01 | 18.19±0.04
AT2023ax | 16.48±0.02 | > 20.5
For AT 2023brc, the presence of strong H-alpha emission nearly 10 days after its maximum optical light and a relatively faint R-band magnitude strongly supports its classification as a nova in M31.
AT 2022abzg was classified by Hornoch et al. (ATEL #15831) as a very slowly evolving nova in M31. Our photometry confirms the classification and shows a possible re-brightening in the optical with a very strong H-alpha excess more than a hundred days after its maximum. There is no doubt that this nova has a very interesting light curve.
AT 2023ax was classified as FeII type nova by Valeev et al. (ATEL #15867). The transient is still showing strong H-alpha excess, though not visible in R-band. This result is consistent with its spectroscopically confirmed nature.
H-alpha images
The work was partially supported by the Ministry of Education and Science of the Republic of Bulgaria, National RI Roadmap Project DO1-176/29.07.2022 and by grant KP-06-M-58/2 of the Bulgarian National Science Fund.
