Spectroscopic observation of AT 2025aeum (2025 outburst of nova M31N 1963-09c) with HCT
ATel #17522; Shatakshi Chamoli (IIA Bengaluru), Judhajeet Basu (IIA Bengaluru), G. C. Anupama (IIA Bengaluru), Sudhanshu Barway (IIA Bengaluru), Vinay Yadav (IIA Bengaluru)
on 2 Dec 2025; 17:06 UT
Credential Certification: Judhajeet Basu (judhajeet.basu@iiap.res.in)
Subjects: Optical, Cataclysmic Variable, Nova
We report spectroscopic observations of the most recent, seventh outburst of the recurrent nova M31N 1963-09c with the HFOSC instrument mounted on the 2m Himalayan Chandra Telescope (HCT), located at the Indian Astronomical Observatory (IAO) in Hanle, India. The outburst was discovered by Zhao et al. on 2025 Nov 25.8076 UT (ATel #17506) and spectroscopically confirmed by Darnley et al. based on a spectrum obtained on 2025 Nov 26.808 (ATel #17516).
We obtained a low-resolution spectrum on 2025 Nov 27.79 UT with an exposure of 3600s, from which only H-alpha and H-beta features could be clearly identified due to the poor S/N. Both lines are very broad, with H-alpha exhibiting a complex multi-peaked feature having an FWHM velocity of approximately 8200 km/s.
This result is consistent with the report by Darnley et al. and past eruptions (ATel #14145, ATel #8242).
We thank the HCT observers for giving us time to carry out the ToO observations. IAO is operated by the Indian Institute of Astrophysics, Bengaluru, India.
