ULL-ASTRO-MASTER discovery of a bright nova in M31 with the Las Cumbres Observatory 40-cm telescope at McDonald Observatory
ATel #17447; A. Caballero-Almagro, J. Basurto Merino, P. G. Berdayes, A. Ceron, M. Contreras, F. Diaz-Segado, T. Ferrer-Lavina, B. Gandolfi, V. Ghiraldo, J. Hernandez Fung, L. Julia-Maroto, E. Lekaroz-Urriza, M. Manzano Garcia, E. Mejia-Martinez, J. Prieto Polo, M. Pulido-Torres, M. Quintana-Ansaldo, A. Schenone-Zanuzzi, A. Selezneva, T. Tundidor Rodriguez, E. Urquijo-Rodriguez (all ULL), M. Abdul-Masih (IAC and ULL), and I. Perez-Fournon (IAC and ULL)
on 18 Oct 2025; 17:39 UT
Distributed as an Instant Email Notice Novae
Credential Certification: Ismael Perez-Fournon (ipf@iac.es)
We report the discovery of a bright nova in M31 (ULL-ASTRO-MASTER-7), reported by us to TNS (AT 2025aapj, E. Mejia-Martinez et al., TNS Astronomical Transient Report No. 273560), with the Las Cumbres Observatory (LCO) 40-cm telescope located at the LCO node at McDonald Observatory, Texas.
The observation, a single exposure of 180 sec in the SDSS g' filter, started on 2025-10-16 at 07:14:35 UT. We detect an uncatalogued source at a position RA (J2000) = 00:40:06.077, Dec (J2000) = +40:48:55.03. We measure an AB magnitude g' = 17.88 +/- 0.08, calibrated against stars of the PanSTARRS-1 DR2 catalogue, uncorrected for Galactic extinction.
Etienne Bertrand (TNS Classification Report No. 22229) has spectroscopically classified this transient as a nova in M31. This nova has been independently discovered by Robert Fidrich and Tamas Tordai (HAA/VSS) and has also been detected by ZTF (ZTF25abxdetz).
Based on observations made with the Las Cumbres Observatory's education network telescopes that were upgraded through generous support from the Gordon and Betty Moore Foundation (program IAC2025B-010). These observations are part of a course in Astrophysical Techniques of the Master in Astrophysics of the Astrophysics Department of the University of La Laguna in collaboration with the Instituto de Astrofisica de Canarias (La Laguna, Tenerife, Canary Islands, Spain).
M31 nova ULL-ASTRO-MASTER-7, AT_2025aapj, LCO g image
