SN 2019vxm – a bright IIn supernova in a faint galaxy

[Robin Leadbeater]

I have confirmed and classified this transient as a type IIn supernova using my ALPY 200 spectrograph (The 31st TNS classification using this setup)

http://www.astronomerstelegram.org/?read=13326

https://wis-tns.weizmann.ac.il/object/2019vxm

It  was mag 15.6 (g) measured from the guider image when the spectrum was taken but the nearby presumed host galaxy is rather faint and until now of unknown redshift. The redshift measured from the spectrum is 0.019

The early rise was caught in the field of the TESS satellite so it will have a detailed light curve. 

Cheers

Robin

[David Swan]

Congrats. It is at a nice northerly declination, so convenient for us. The transient is located near the Cyg-Cep-Dra intersection, which is halfway up the zenith for me at 2100 at this time of year. I’ll try to capture an image tomorrow.

[Robin Leadbeater]

This is how it looked in the guider 2019-12-01T17:18:12    3 hours after the discovery was announced (South is up)

[Dr Andrew Smith]

Well done Robin. Did you miss posting the image? 

Regards Andrew 

[David Swan]

It is all very mysterious, Andrew. If I look at the thread on my laptop, Robin’s image is there to see (there’s a green circle around the transient, and red circles around photometric comparison stars). There is an empty box where the image should be when I look on my ipad, and no box at all when I look on my phone! And I initially thought your comment was a bit passive aggressive. I do apologise for my uncharitable – and fortunately private – reaction.

[Dr Andrew Smith]

Noble of you to lay bare your private thoughts. I think I have a jinx with the web site.

Regards Andrew 

[David Swan]

Midpoint 2019/12/06 17:31 UT

Pos Angle +93° 35.7′, FL 391.6 mm, 1.26″/Pixel

[David Swan]

Taken through a luminance filter only, with zeropoint from UCAC4 R mags, the SN comes out around R = 14.4

The timestamp is slightly wrong. I leave Astrometrica to take the start of exposures from individual FITS for track and stack (which is correct). It won’t automatically read the midpoint value put in the header by Maxim when I do a prior stack in that software. Of course I could input the midpoint manually into Astrometrica using the image parameters menu…

[Dr Paul Leyland]

Unfortunately, I see no image with Chromium on a Ubuntu system.

Looks like the web site not be as portable as desired.  8-(

[Dr Paul Leyland]

Unfortunately, I see no image with Chromium on a Ubuntu system. Looks like the web site not be as portable as desired 8-(

This is what the HTML looks like which, incidentally, gives the URL of the image:

This is how it looked in the guider 2019-12-01T17:18:12 3 hours after the discovery was announced (South is up)

Nothing obviously wrong so perhaps it’s in the CSS?

[David Swan]

I’ll mention the issue to Dominic Ford at the next webops (if he doesn’t pick this up before that).

[Robin Leadbeater]

It appears on my pc (win 7 /chrome) but not in another chromium based browser or on my phone (android/chrome)

Here it is again in case it was a one off glitch

[Robin Leadbeater]

I have just posted the image again here

https://britastro.org/comment/7489#comment-7489

and strangely the original image now appears everywhere it should !  Work that one out 

[Robin Leadbeater]

If the redshift based distance (~80Mpc) is correct, mag 14.4 works out at an impressive absolute magnitude of -20.2 , thought to be boosted by interaction with circumstellar material in the case of type IIn

Robin

[Dr Andrew Smith]

I was beginning to think it was me!

Regards Andrew 

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