PSN J01364816+1545310 in M74

Information about outbursts of eruptive stars, Be activity, ...
Paolo Berardi
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Joined: Thu Sep 29, 2011 10:51 pm

PSN J01364816+1545310 in M74

Post by Paolo Berardi »

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

Not yet confirm observations.

Paolo
Paolo Berardi
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Re: PSN J01364816+1545310 in M74

Post by 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):

Image

Spectral profile:

Image

Gelato recognition list:
Image

Gelato 1st candidate:
Image

Gelato 2nd candidate:
Image

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
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Re: PSN J01364816+1545310 in M74

Post by Robin Leadbeater »

Hi Paolo,

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

Cheers
Robin
LHIRES III #29 ATIK314 ALPY 600/200 ATIK428 Star Analyser 100/200 C11 EQ6
http://www.threehillsobservatory.co.uk
Paolo Berardi
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Joined: Thu Sep 29, 2011 10:51 pm

Re: PSN J01364816+1545310 in M74

Post by 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:
Image

Paolo
Francois Teyssier
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Re: PSN J01364816+1545310 in M74

Post by 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
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Re: PSN J01364816+1545310 in M74

Post by 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
LHIRES III #29 ATIK314 ALPY 600/200 ATIK428 Star Analyser 100/200 C11 EQ6
http://www.threehillsobservatory.co.uk
Paolo Berardi
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Joined: Thu Sep 29, 2011 10:51 pm

Re: PSN J01364816+1545310 in M74

Post by 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
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Re: PSN J01364816+1545310 in M74

Post by Robin Leadbeater »

Paolo Berardi wrote:
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
LHIRES III #29 ATIK314 ALPY 600/200 ATIK428 Star Analyser 100/200 C11 EQ6
http://www.threehillsobservatory.co.uk
Paolo Berardi
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Joined: Thu Sep 29, 2011 10:51 pm

Re: PSN J01364816+1545310 in M74

Post by 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).

Image

Ciao
Paolo
Christian Buil
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Re: PSN J01364816+1545310 in M74

Post by Christian Buil »

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

Image

Excellent subject for comparison with Paolo's latest spectrum.

Christian
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