SN 2021aefx in NGC1566 (Dorado)

[Robin Leadbeater]

https://www.wis-tns.org/object/2021aefx
A supernova in a nearby galaxy for southerly observers to keep an eye on. Caught early so currently quite faint. The sub type is unclear from the initial spectrum but in the absence of IS extinction a type Ia could potentially reach as bright as mag 11 if the distance (10 Mpc but with high uncertainty) in NED is correct.

Cheers
Robin

EDIT: a good target for 2SPOT perhaps ?

[2SPOT]

Yes Robin, we did it this morning : RC 12 inch and Alpy 600 from Deep Sky Chile

Here's the Sn in NGC 1566



And the spectrum

[Robin Leadbeater]

Nice catch! So it is confirmed as a Ia, Do you have an estimate of the brightness? The spectrum does not look obviously reddened so it could be heading for being the brightest SN for some time

Cheers
Robin

[2SPOT]

Hi Robin,

I think the Sn is around mag. V=15,5

Here's a quick comparison with others stars in the field

[Hamish Barker]

great work, such a nice composition too with the big spiral galaxy!

[Robin Leadbeater]

Still rising rapidly in the ASAS-SN forced photometry data (Latest Mag 13.6 but that is likely an over estimate given contamination from the galaxy)
https://asas-sn.osu.edu/sky-patrol/coor ... d7d7314ceb

Cheers
Robin

[Terry Bohlsen]

Hi All
I took a spectrum of this SN last night with my LISA. R=~1600
Cheers
Terry

[Robin Leadbeater]

There is an image using SLOOH from last night on the BAA forum where it looks to be ~mag 13.5
https://britastro.org/comment/11199#comment-11199
and running the 2SPOT spectrum through SNID, it estimates it was ~10-12 days away from maximum then so maximum around 25th. Plenty of time for it to get a lot brighter yet.

SN2021aefx_SNIDFIT_2SPOT_20211114.png (48.25 KiB) Viewed 11545 times

[Robin Leadbeater]

It has now reached maximum at mag 12 (g)

https://asas-sn.osu.edu/sky-patrol/coor ... 19daf1e0b5

Robin

[2SPOT]

Last spectrum of this Sn taken this morning.



And comparison with our spectrum taken November 14th