Bright optical transient in M31
ATel #16095; A. Valcheva (Sofia University, Bulgaria) and A. Kostov (IA and NAO, BAS, Bulgaria)
on 25 Jun 2023; 17:13 UT
Credential Certification: Antoniya Valcheva (valcheva@phys.uni-sofia.bg)
Subjects: Optical, Nova, Transient
Referred to by ATel #: 16127
We report the discovery of a bright optical transient in M31 on 5x300 sec co-added R-band CCD images taken on 2023 June 23.9939 UT with the 50/70 Schmidt telescope at Rozhen NAO, Bulgaria. The object is located at R.A.=00h41m54s.20, Decl.=+41o10'16".6 (equinox 2000.0), which is 565.0'' west and 351.9'' south of the center of M31. (Discovery image can be found here ).
We detected an increase in the transient's brightness on 5x300 sec co-added R-band images taken on 2023 June 24.9979 UT with the same instrumentation. R-band magnitudes are shown below:
2023 June 23.9939 UT R=18.81 ± 0.07 mag 5x300 sec
2023 June 24.9979 UT R=17.64 ± 0.03 mag 5x300 sec
Additional B-band magnitude is also available:
2023 June 25.0021 UT B=17.97 ± 0.03 mag 3x300 sec
The search in our optical long-term BVR monitoring of M31 shows no object visible at that position and the nearest object in the online databases is located at a distance of 0.''812 and have r=20.962 mag (Chambers+, 2016).
The strong rise in 24 hours and the color of the transient leads to the conclusion that this is a nova candidate in M31. Spectroscopic observations are strongly recommended to reveal the transient's nature.
This study is financed by the European Union-NextGenerationEU, through the
National Recovery and Resilience Plan of the Republic of Bulgaria, project SUMMIT BG-RRP-2.004-0008-C01 in part and by the Ministry of Education and Science of the Republic of Bulgaria, National RI Roadmap Project DO1-176/29.07.2022.
