Detected H-alpha emission from nova candidate M81N 2023-02a
ATel #15912; A. Valcheva (Sofia University, Bulgaria), M. Minev, A. Kurtenkov, I. Dimitrova (IA and NAO, BAS, Bulgaria)
on 21 Feb 2023; 19:52 UT
Credential Certification: Antoniya Valcheva (valcheva@phys.uni-sofia.bg)
Subjects: Optical, Nova, Transient
We report strong H-alpha emission from M81 candidate nova M81N 2023-02a independently discovered by Hornoch et al. on 2023 Feb. 10.934 UT (PNV J09560893+6902443; ATel #15896) and the Italian Supernovae Search Project (ISSP) on 2023 Feb 10.85788 UT ( AT 2023bnl).
Our observations were performed in R and H-alpha (FWHM of 3 nm) filters with the FoReRo2 focal reducer at the 2m RCC telescope at NAO Rozhen, Bulgaria in two consecutive nights. For photometric calibration of the R and H-alpha (AB system) magnitudes, we used standard non emission stars from Stetson photometric standard stars. The photometric results for the transient are presented below:
2023 Feb 17.004 UT R=19.62±0.04 mag (3x300 sec)
2023 Feb 17.055 UT mH-alpha=17.76 ±0.04 (3x300 sec)
2023 Feb 17.958 UT R=20.11±0.05 mag (7x120 sec)
2023 Feb 17.977 UT mH-alpha=17.31±0.03 (5x300 sec)
The results are consistent with the properties of novae, namely increasing flux in H-alpha with the fading optical brightness.
R and Halpha images of the M81 nova candidate
The work was partially supported by the Ministry of Education and Science of the Republic of Bulgaria, National RI Roadmap Project D01-383/18.12.2020 and by grant KP-06-M-58/2 of the Bulgarian National Science Fund.
