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SN 2021aefx in NGC1566 (Dorado)

Posted: Sat Nov 13, 2021 12:20 am
by 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 ?

Re: SN 2021aefx in NGC1566 (Dorado)

Posted: Sun Nov 14, 2021 12:14 pm
by 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
Image


And the spectrum

Image

Re: SN 2021aefx in NGC1566 (Dorado)

Posted: Sun Nov 14, 2021 12:47 pm
by 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

Re: SN 2021aefx in NGC1566 (Dorado)

Posted: Sun Nov 14, 2021 3:11 pm
by 2SPOT
Hi Robin,

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

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

Image

Re: SN 2021aefx in NGC1566 (Dorado)

Posted: Tue Nov 16, 2021 6:13 am
by Hamish Barker
great work, such a nice composition too with the big spiral galaxy!

Re: SN 2021aefx in NGC1566 (Dorado)

Posted: Tue Nov 16, 2021 2:04 pm
by 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

Re: SN 2021aefx in NGC1566 (Dorado)

Posted: Wed Nov 17, 2021 7:44 am
by Terry Bohlsen
Hi All
I took a spectrum of this SN last night with my LISA. R=~1600
Cheers
Terry
sn2021aefx_20211116_436_TBohlsen.png

Re: SN 2021aefx in NGC1566 (Dorado)

Posted: Wed Nov 17, 2021 5:26 pm
by 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
SN2021aefx_SNIDFIT_2SPOT_20211114.png (48.25 KiB) Viewed 7834 times

Re: SN 2021aefx in NGC1566 (Dorado)

Posted: Tue Nov 30, 2021 2:00 pm
by Robin Leadbeater
It has now reached maximum at mag 12 (g)

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

Robin

Re: SN 2021aefx in NGC1566 (Dorado)

Posted: Fri Dec 03, 2021 10:57 am
by 2SPOT
Last spectrum of this Sn taken this morning.

Image

And comparison with our spectrum taken November 14th

Image