AT 205nlr: a Galactic nova?

A potential Galactic nova is being discussed:

  • AT 205nlr from ASASSN - internal name ASASSN-25cm => Astro-COLIBRI
  • reported also here
  • exchange from two amateur astronomers discussing their obs, with some caveats of their estimates for the magnitude based on comparison star selection

=> help with the confirmation of the magnitudes + classification is very welcome

AT 2025nlr has indeed been classified as a classical nova explosion.


AT 2025nlr has a Gaia-GBp Mag 7.8 since last night… An easy target. 2 seconds of exposure only.
Sincerely,
Roger Hellot
AITP Observatory at SpaceObs SanPedro-Atacama-Chili*
TRBS Observatory at Rosheim (F-67560)*

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Thanks a lot for sharing this! Continued monitoring over the next days and weeks is very important for tis kind of target.

I was just outside and made a visual observation of 6.4 magnitude.
Comp stars from AAVSO; 58, 60, 63
Bright and easy to see.

Andrew

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2025-06-26 G bp 6.25
2025-06-26 G rp 6.26

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Still extremely bright! An easy target to keep an eye on…
The nova has in the meantime also been detected to emit high-energy gamma-rays!