5 December 2019 at 9:46 pm #574467
I have confirmed and classified this transient as a type IIn supernova using my ALPY 200 spectrograph (The 31st TNS classification using this setup)
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.
Robin5 December 2019 at 10:11 pm #581710
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.5 December 2019 at 10:32 pm #581711
This is how it looked in the guider 2019-12-01T17:18:12 3 hours after the discovery was announced (South is up)6 December 2019 at 8:42 am #581714
Well done Robin. Did you miss posting the image?
Regards Andrew6 December 2019 at 5:50 pm #581724
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.6 December 2019 at 5:55 pm #581725
Noble of you to lay bare your private thoughts. I think I have a jinx with the web site.
Regards Andrew6 December 2019 at 6:03 pm #581726
Midpoint 2019/12/06 17:31 UT
Pos Angle +93° 35.7′, FL 391.6 mm, 1.26″/Pixel6 December 2019 at 6:31 pm #581727
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…6 December 2019 at 7:55 pm #581728Paul LeylandParticipant
Unfortunately, I see no image with Chromium on a Ubuntu system.
Looks like the web site not be as portable as desired. 8-(6 December 2019 at 8:07 pm #581729Paul LeylandParticipant
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?6 December 2019 at 8:28 pm #581730
I’ll mention the issue to Dominic Ford at the next webops (if he doesn’t pick this up before that).6 December 2019 at 8:36 pm #581731
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 glitch6 December 2019 at 8:41 pm #581732
I have just posted the image again here
and strangely the original image now appears everywhere it should ! Work that one out6 December 2019 at 8:49 pm #581733
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
Robin6 December 2019 at 10:27 pm #581735
I was beginning to think it was me!
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