H-alpha detection and optical monitoring of the bright M31 nova AT 2022npa
ATel #15497; A. Valcheva (Sofia University, Bulgaria), P. Nedialkov (Sofia University, Bulgaria), E. Ovcharov (Sofia University, Bulgaria)
on 4 Jul 2022; 21:17 UT
Credential Certification: Antoniya Valcheva (valcheva@phys.uni-sofia.bg)
Subjects: Optical, Nova, Transient
We report H-alpha detection of the recent nova in M31 - AT2022npa (= XM74MZ) (= PNV J00425478+4115086). The transient was reported by Mi Zhang and Xing Gao (Xingming Obs) on 2022/06/25.874 to have 17.9 unfiltered magnitude.
Our observations in the narrowband H-alpha (FWHM of 3 nm) were carried out in the direct focus and with the FoReRo2 focal reducer at the 2m RCC telescope at NAO Rozhen, Bulgaria. The H-alpha photometry shows a bright object with slowly increasing brightness which supports the classification of the transient as a nova. The magnitudes were obtained from 3x300 sec co-added images and are as follows:
2022 June 30.0037 UT Ha=16.25±0.02 FoReRo2
2022 June 30.9999 UT Ha=15.89±0.02 FoReRo2
2022 July 03.9796 UT Ha=15.59±0.02 direct focus
We also performed BR follow-up observations carried out with the FoReRo2 focal reducer at the 2m RCC telescope and the 50/70 cm Schmidt telescope at NAO Rozhen, Bulgaria. Interestingly, the photometry testifies a gradual rise also in B- and R-bands. All magnitudes are summarized below:
2022 June 29.0271 UT R=18.17±0.14 5x300 sec Schmidt
2022 June 29.9958 UT R=17.98±0.04 3x120 sec FoReRo2
2022 June 30.9920 UT R=17.83±0.04 3x120 sec FoReRo2
2022 July 01.9799 UT R=17.66±0.07 5x300 sec Schmidt
2022 June 29.0041 UT B=18.81±0.13 3x300 sec Schmidt
2022 June 30.0037 UT B=18.56±0.04 3x180 sec FoReRo2
2022 June 30.9972 UT B=18.37±0.03 3x180 sec FoReRo2
2022 July 01.9987 UT B=17.95±0.05 3x300 sec Schmidt
Spectral observations are strongly recommended.
The work was partially supported by the Ministry of Education and Science of the Republic of Bulgaria, National RI Roadmap Project DO1-383/18.12.2020 and NSF Bulgaria grant DN18/10-11.12.2017.
