AT2020adow - possible supernova in a low redshift galaxy

[Robin Leadbeater]

https://wis-tns.weizmann.ac.il/object/2020adow
Discovered on the rise at mag 16.2 in KUG 0830+278, redshift 0.007

No chance for me tonight as storm Bella sweeps through

Cheers
Robin

[Rainer Ehlert]

https://wis-tns.weizmann.ac.il/object/2020adow
Discovered on the rise at mag 16.2 in KUG 0830+278, redshift 0.007

No chance for me tonight as storm Bella sweeps through

Cheers
Robin

Hi Robin,

Interesting. I just converted the J2000 to JNow coordinates and the AT2020adow is inside the Galaxy PGC24012 mag 15.5 and a size of 51.0" x 30.0" according to my planeatrium program.

JNow
RA 04h 34m 54.6s
DEC +27° 38' 33"

Do not know if at mag 16.2 I would locate it. Will take a look if I have clear sky tonight. A little bit late here but I think it is worthwhile looking for it.

Fortunately there are 3 nice stars like a pointer pointing on the Galaxay

AT2020adow_PGC24012.JPG (20.32 KiB) Viewed 7129 times

[Rainer Ehlert]

Hi,

I managed to find the place and there are the three stars ponting to the Galaxy. Now I need to wait for the AT 2020adow get to a mag of about 13 in order to be able to place it in the slit.

PGC24012_20201226.jpg (117.54 KiB) Viewed 7100 times

[Robin Leadbeater]

Yes it is going to be a tough one but it should be just possible to separate it from the galaxy core if it gets bright enough. The moon is also now a problem of course. Here is how observability looks from near my location.
https://observability.date/chart/obsid: ... :27.712114

Cheers
Robin

[Rainer Ehlert]

Yes it is going to be a tough one but it should be just possible to separate it from the galaxy core if it gets bright enough. The moon is also now a problem of course. Here is how observability looks from near my location.
https://observability.date/chart/obsid: ... :27.712114

Cheers
Robin

Hi Robin,

Yes, closest approach will be on January 1st at about 5°.

May I ask how bright will it get or is this not possible to predict ?

The host Galaxy is about 119 million light years away.

[Robin Leadbeater]

The host Galaxy is about 119 million light years away.

Hi Rainer,

It depends on the type and the extinction in the host galaxy but at that distance a type Ia would be expected to reach around mag 13.5 in the absence of any extinction

Where does that figure come from? I could not find any redshift independent distances in NED and measurements based on nearby redshifts can be rather uncertain. A type Ia would allow a measurement of the actual distance

Cheers
Robin

[Robin Leadbeater]

It has now been classified as a broad lined type Ic. Spectrum here
https://www.wis-tns.org/object/2020adow

These are quite rare. (type Ic are stripped envelope core collapse supernovae with without H emission but these have broader lines indicating with unusually high velocity, Possibly connected to long duration GRB). They typically have absolute magnitudes similar to or brighter than type Ia so could be worth keeping an eye on

Cheers
Robin

[Rainer Ehlert]

It has now been classified as a broad lined type Ic. Spectrum here
https://www.wis-tns.org/object/2020adow

These are quite rare. (type Ic are stripped envelope core collapse supernovae with without H emission but these have broader lines indicating with unusually high velocity, Possibly connected to long duration GRB). They typically have absolute magnitudes similar to or brighter than type Ia so could be worth keeping an eye on

Cheers
Robin

Hi,

What happened with this Supernova ? No more information on the www.wis-tns.org site anymore ...

[Robin Leadbeater]

Hi,

What happened with this Supernova ? No more information on the http://www.wis-tns.org site anymore ...

Hi Rainer

TNS is just for confirming, classifying and naming transients. Once this has been done there are normally no further updates unless follow ups suggest a change in classification. It might end up in a paper in while like these (I am a co-author as I took a confirming spectrum of one of them)
https://ui.adsabs.harvard.edu/abs/2020A ... D/abstract

This is what AT2020adow looked like a couple of nights ago with the modified ALPY 200 compared with a Ic from SNID (It was about mag 14.5 from the guider image)

SN2020adow_SNIDfit_SN1994I.png (56.08 KiB) Viewed 6893 times

and compared with the professional classification spectrum a few days earlier (note the narrow H alpha line from the host galaxy and how the radial velocity of the broad absorption lines seen in the spectrum has reduced between the two dates, making my spectrum appear relatively redshifted

sn2020adow_20210101_956_Leadbeater.png (37.8 KiB) Viewed 6893 times

Cheers
Robin

[Robin Leadbeater]

Here it is in the guider image. Its brightness completely dominates the host galaxy (note the very bright sky background from the moon. Despite this it was still possible to get a reasonable spectrum)

SN2020adow_guider_20201010.png (149.49 KiB) Viewed 6892 times