Liverpool Telescope SPRAT spectrum of the M31 Recurrent Nova AT 2025aeum (M31N 1963-09c)
ATel #17516; M. J. Darnley (LJMU), Jianlin Xu, Mi Zhang, Hualin Li, Ziyang Mai, Yanxi Li, Wenjie Zhou, Jingyuan Zhao, Guoyou Sun, Jiangao Ruan, Xing Gao (Xingming Observatory)
on 1 Dec 2025; 09:31 UT
Credential Certification: Matt Darnley (matt_darnley@icloud.com)
Referred to by ATel #: 17522
The recent nova eruption in M31 AT 2025aeum has been confirmed as the seventh observed eruption of the five-year recurrent nova M31N 1963-09c (ATel #17506).
We obtained a pair of 600s spectra of AT 2025aeum with the SPRAT instrument on the Liverpool Telescope on 2025 Nov 26.808 (mid-point).
There is a clear detection of broad and double peaked Balmer line emission from Hα, Hβ, and Hγ.
There are also a strong detections of N III (4641) and He I (4471). N II (5680) and He II (4685) are also present. There is also evidence of a N II, or possibly He I, emission line at around 5010 Angstroms.
The Hα emission complex has a full-width of around 8000 km/s. The separation of the two peaks is around 4500 km/s.
As such, the spectrum of AT 2025aeum is completely consistent with a short recurrence period nova in M31.
