AT 2023oom - possible nova in M31?

Magyar Csillagaszati Egyesulet, Valtozocsillag Szakcsoport (Hungary) (MCSE)
Mon, 08/07/2023 - 01:48

I found a 19.5 magnitudes bright extragalactic nova candidate on my 10x120s stacked images made with Luminance filter using a 0.51m telescope Utah Desert Remote Observatory /UDRO/ at Great Basin Desert, Beryl Junction, Utah, USA (iTelescope,net network) on 2023 August 5  09:02UT.

Preliminary co-ordinates: 00 43 56.392 +42 08 46.42 (J2000.)

More info on the TNS server: AT 2023oom and CBAT TOCP website: PNV J00465260+4201428 and my website:

The ZTF data (especially from 25 July) mined out by Jingyuan Zhao suggest that this is a blue object, thus likely not an LPV.

Spectrum and multicolor follow-up photometry are urgently  needed!


Magyar Csillagaszati Egyesulet, Valtozocsillag Szakcsoport (Hungary) (MCSE)
Located near M31N 2008-12a

Actually this nova candidate (Vend51  = AT 2023oom = PNV J00465260+4201428) is located only 17.3' distance from M31N 2008-12a, thus the area might have been quite frequently monitored in the past decade. Maybe it would be worth to investigate archive M31N 2008-12a images for checking the past behaviour of At 2023oom.

Magyar Csillagaszati Egyesulet, Valtozocsillag Szakcsoport (Hungary) (MCSE)
Accelerated brightening of the slow nova AT 2023oom (Vend51) in

The extragalactic slow nova AT 2023oom (Vend51) has been significantly brightening at an accelerated rate in the last few days!
Tamás Tordai measured it at 18,341CV Jan. 1.79UT, recent ZTF data show it at 18.153r Saturday (January 6) morning.

Photometry by Tamás Tordai:
AT2023oom 2460305.28908 18.782CV (0.076)
AT2023oom 2460309.38930 18.472CV (0.067)
AT2023oom 2460311.36725,18.464CV (0.068)
AT2023oom 2460314.29222 18.340 CV (0.037)

ZTF light curve:

Spectroscopic observations and multicolor follow-up photometry (especially with R-band and H-alpha filters) are urgently  needed!