subluminous or high extinction?

Home Forums Deep Sky possible supernova AT 2021aai in NGC 2268 subluminous or high extinction?

#583727
Robin Leadbeater
Participant

Well the distance to NGC2268 is probably reasonably accurate as it based on Ia supernova 1982B (which was V mag 13.5 when discovered just past maximum) so assuming this object is say mag 17.5 at maximum this gives it an absolute magnitude of -14.8 There is then 0.2 mag extinction from our own galaxy giving abs mag v mag ~ -15 which is very much at the low end  but not unknown for supernovae eg

https://arxiv.org/abs/astro-ph/0112051

but if there is a lot of extinction in the host galaxy it could be higher luminosity of course.

(It could also be a foreground CV of course. We need a spectrum)

It is interesting that there has been no published professional classification yet. Maybe it is something interesting and the classification is being withheld. (Not unknown. Classifications can be submitted to TNS with an embargo)

Cheers

Robin