Optical (R and H-alpha) nova candidate in M31 and H-alpha confirmation of the probable nova 2015-09a
E. Ovcharov, A. Kurtenkov, V. Bozhilov, A. Valcheva, P. Nedialkov (University of Sofia, Bulgaria), A. Kostov (IA-NAO, BAS)
We report the discovery of a probable nova located at RA(2000) = 00h42m14.49s, Dec(2000) = +41d17'34.24", which is 336.3" West and 85.7" North of the center of M31. The images are obtained with the 2m RCC telescope, equipped with focal reducer FoReRo2 at NAO Rozhen, Bulgaria. The R- and H-alpha magnitudes for this object and for the probable nova TCP J00424034+4119295 = 2015-09a (ATel #8048) are: 2015-09b? 2015 09 15.858 UT, R=19.55+/-0.16 (5x120s) 2015 09 16.915 UT, Ha=17.14+/-0.04 (3x180s) 2015 09 16.906 UT, R=19.45+/-0.15 (5x120s) 2015 09 17.967 UT, Ha=17.11+/-0.05 (3x180s) 2015 09 17.958 UT, R=19.66+/-0.16 (5x120s) TCP J00424034+4119295 = 2015-09a 2015 09 15.858 UT, R=15.24+/-0.01 (5x120s) 2015 09 16.915 UT, Ha=14.36+/-0.01 (3x180s) 2015 09 16.906 UT, R=15.48+/-0.01 (5x120s) 2015 09 17.967 UT, Ha=14.04+/-0.01 (3x180s) 2015 09 17.958 UT, R=15.66+/-0.01 (5x120s) The presence of H-alpha excess for the nova candidate (2015-09b?) and the increasing H-alpha excess for the 2015-09a strongly supports their classification as novae. Additional observations are required, particularly spectroscopy.
optical,nova