PSN J01364816+1545310 in M74

[Paolo Berardi]

http://www.cbat.eps.harvard.edu/unconf/ ... 45310.html

Not yet confirm observations.

Paolo

[Paolo Berardi]

Voila la dernier supernova parmi les nombreux allumé par Olivier pour le stage spectro OHP 2013! (by Giovanna)

Not an easy object due to Moon glare and poor sky transparency. Anyway I and Giuseppe yesterday tried to take a spectrum with Lhires III 150 l/mm, 10 x 480 sec. PSN is situated just SE of galaxy nucleus, on main arm. In this old image it is shown the position (double circle):



Spectral profile:



Gelato recognition list:


Gelato 1st candidate:


Gelato 2nd candidate:


Also this one seems to be a type II supernova, although only further observations during the evolution can confirm this classification.

Ciao
Paolo

[Robin Leadbeater]

Hi Paolo,

You should probably report this. Yours could be the first confirming spectrum

Cheers
Robin

[Paolo Berardi]

Robin, I'm not yet registered to CBAT. I do not know where else I can submit the observation...

Slit view alternating with galaxy field:


Paolo

[Francois Teyssier]

Hello Paolo,

You can report observations to

dbishopx at gmail.com or dbishop at vhdl.org

the author of Latest supernovae page :

http://www.rochesterastronomy.org/supernova.html

A yahoo group : http://tech.groups.yahoo.com/group/isn_chat/

Cheers

François

[Robin Leadbeater]

Now confirmed as type II
http://www.astronomerstelegram.org/?read=5228

I asked the AAVSO on the best way to get official recognition of a confirming spectrum. They suggested going through CBAT or ATEL. You need a tame pro for ATEL though. See reply here
http://www.aavso.org/bright-transient-m ... 61545310-0

Cheers
Robin

[Paolo Berardi]

François and Robin, thank you both!

I read now (just come back from a short journey) and see related ATEL and CBET...

This transient is now SN 2013ej (type II, core-collapse event)

I'll read CBAT "How to report discovery", anyway I was told that we can try to send an email with normal descriptive text to cbatiau-AT-eps.harvard.edu.

It seems these SN types in early stage are not very easy to classify for their "flat" spectral profile. A better SNR would give greater confidence, however GELATO does not seem to confuse with other SN types (ATEL 5228 reports a fit with SN1999gi, the same of our). As I said we had a strong lunar glare and poor transparency (bright sky, high background solar spectrum with related noise). Usually this is not a mag 12.5 SNR...

We hope to do better and be faster next time!

Ciao
Paolo

[Robin Leadbeater]

We hope to do better and be faster next time!

Well your spectrum was taken 14 hours earlier and reported here and relayed by me to the AAVSO forum before the ATEL was issued so that makes you first in my view.

Robin

[Paolo Berardi]

Thank you Robin!

From AAVSO lightcurve seems that the SN was fainter than mag 12.4. First measures (near to our observation of 27 july) are mag V 13.0 and V 12.8.

Yesterday we took a new spectrum obtaining a better SNR probably due to concurrence of a lower moonlight, better transparency and a slightly higher SN brightness. Furthermore the spectrum begins to be characterized. It shows blue shifted absorption Balmer lines (P-Cyg profiles).



Ciao
Paolo

[Christian Buil]

Spectrum taken during OHP spectro workhop (T200 mm telescope, Alpy600, Atik460EX):



Excellent subject for comparison with Paolo's latest spectrum.

Christian