AstroNote 2024-258

We report the following transient classifications.

Targets were supplied by the BlackGEM, XOSS, MASTER, GOTO and ASAS-SN surveys.

Observations were performed on the ESO New Technology Telescope (NTT) at La Silla on the night of 2024 September 14, while testing on-site the Scheduler of the incoming SOXS instrument, using EFOSC2 and Grism 13 (3680-9270 A, 17 A resolution). Classifications were done using SNID (Blondin & Tonry 2007 2007ApJ...666.1024B).

The classification spectra and additional details can be obtained from http://www.pessto.org (via WISeREP) and the IAU Transient Name Server.

The spectrum of AT 2024vjm is peculiar: it shows a yellowish continuum and lines with deep P Cygni profiles having an expansion velocity of about 2000 km/s. We can identify strong Fe II lines, which agrees with a Nova classification. On the other hand, the object shows a slow photometric evolution, unusual from a Nova, and is currently around absolute magnitude -11, which would make it one of the brightest known Nova.
Therefore, we propose the classification as a peculiar Nova, though we cannot rule out other, more exotic scenarios, such as an eruption from a yellow hypergiant star.
Further spectroscopic observations are encouraged.

The spectrum of AT 2024uuv is that of a K-type star, with absorption lines from metals, Ca II H&K and the 4000 A break. The object was proposed as a candidate Microlensing Event.

The classified objects are listed in the Related Objects table below.