GOTO detection of the M31 nova M31N 2008-12a
D. K. Galloway (Monash), K. Ackley (Monash), K. Wiersema (Warwick), M. Dyer (Sheffield), J. Lyman (Warwick), K. Ulaczyk (Warwick), D. Steeghs (Warwick), V. Dhillon (Sheffield), P. O'Brien (Leicester), G. Ramsay (Armagh), S. Poshyachinda (NARIT), R. Kotak (Turku), L. Nuttall (Portsmouth), D. Pollacco (Warwick), R. Breton (Manchester), for the GOTO collaboration
We report the detection of the recurrent M31 nova M31N 2008-12a (ATel #14130) on 2020-10-30 19:58:11 (MJD 59152.83207), during its most recent outburst. In three visits between 19:58 to 23:35 with the Gravitational-wave Optical Transient Observer (GOTO) prototype on La Palma, each comprising a series of 3 90-s exposures in our wide (400-700 nm) L-band filter, we found the nova at an estimated g-band magnitude of 18.74+/-0.17 on average, based on cross-calibration against PanSTARRS DR1 photometry in ATLAS_REFCAT2 (Tonry et al. 2018).

Our earliest detection is approximately 90 minutes earlier than the Liverpool Telescope discovery (ATel #14130). The source was undetectable on the previous visit to the field, on 2020-10-30 03:34:25 (MJD 59152.14890); the deepest 5-sigma limit obtained around the same time was 19.4.

Observations are continuing.

GOTO is operated at the La Palma observing facilities of the University of Warwick on behalf of a consortium including the University of Warwick, Monash University, Armagh Observatory, the University of Leicester, the University of Sheffield, the National Astronomical Research Institute of Thailand (NARIT), Turku University, Manchester University, Portsmouth University and the Instituto de Astrofisica de Canarias (IAC) (https://goto-observatory.org)
optical,nova,transient