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SN 2018cow

Posted: Sun Jun 24, 2018 1:29 pm
by Peter Somogyi
A very faint object:
http://www.astronomerstelegram.org/?read=11727
http://www.rochesterastronomy.org/sn2018/sn2018cow.html
https://wis-tns.weizmann.ac.il/object/2018cow

My observation from last night - bluish featureless continuum:
sn2018cow.gif
sn2018cow.gif (18.61 KiB) Viewed 14293 times
Guide view (off slit guiding):
guide_sn2018cow.png
guide_sn2018cow.png (141.73 KiB) Viewed 14293 times
The peak where H-alpha should be doesn't seem to be hotpixel: it's 100A away, and when applying the background galaxy's redshift (4241 +/- 39 km/s), I can measure 6561.2A as its barycenter. So that may be from the galaxy.
The "W" shape (absorptions barycenters: 4912A, 4967A) should be also something real (SNR good enough in the green-blue), but none matching by any atel reports.
I will be interested in comparing our results and learn more, here is mine:
asdb_sn2018cow_20180623_915.zip
(9.24 KiB) Downloaded 749 times
Peter

Re: SN 2018cow

Posted: Mon Jun 25, 2018 9:20 am
by Robin Leadbeater
Hi Peter,

Very interesting. This is certainly an odd object. (There are now 30 ATels on this !) I would have expect some clear features in the spectrum by now if it was a normal supernova. I ran it through SNID but it did not come up with any matches.

Cheers
Robin

Re: SN 2018cow

Posted: Wed Jun 27, 2018 5:49 pm
by Peter Somogyi
Thank you for the look, Robin!
ATEL#11776 also reports vanishing features on the next day (2018-06-24 21:22).
It would be nice to access those spectra as fits files, for a comparison.
Also curious how was the result (overlapping observation with mine) with the T60 at Club Mars.

Peter

Re: SN 2018cow

Posted: Fri Jan 11, 2019 10:21 pm
by Robin Leadbeater
An update on this strange object. We still do not know what it is. It could be a new type of supernova or a tidal disruption event
https://www.skyandtelescope.com/uncateg ... stronomers
(Thanks to David Swan on the BAA forum for the link)

Robin