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Supernova in NGC 1365

Posted: Mon Oct 29, 2012 6:07 am
by Christian Buil
An observation of the very southern SN in NGC 1365 discovered by
Alain Klotz by using TAROT telescope (Chili). My spectrum is taken with
a Celestron 11 and a LISA spectrograph. Date 29/10/2012 (one day
after discorering date). From France the elevation is only 7° +
artificial pollution + full moon... and a V=14 magnitude only.
Very special spectroscopy

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Voici l'observation du spectre de la supernova découverte par A. Klotz le 28,
dépouillé sur le pouce, la nuit même. La prochaine fois, Alain tu les
trouves plus haute pour les nordistes ! Un peu sport : j'ai
fait le spectre sans voir la SN dans la caméra guide (poses de
10 secondes pourtant). Je la sors en posant entre 30 et 60 secondes
(l'absorption atmosphérique est considérable).

Image

La particularité : la SN était en moyenne entre 6 et 7° au dessus de
l'horizon, j'ai observé comme d'habitude dans des conditions urbaines,
et on avait la pleine. Et une supernova de magnitude 14 seulement.
Cool de voir que l'on peut faire un objet aussi faible et aussi sud.

Version non comprimée ici (uncrompressed version) :

http://www.astrosurf.com/buil/forum/_ngc1365_poster.png

Christian B

Re: Supernova in NGC 1365

Posted: Mon Oct 29, 2012 6:19 am
by Olivier GARDE
Bravo Christian,

A cette hauteur, tu as du capter le spectre des vapeurs des pôts d'échappements :P

Bon, celà me motive pour accélérer la mise en place de mon observatoire dans ma nouvelle demeure.

Re: Supernova in NGC 1365

Posted: Mon Oct 29, 2012 10:54 am
by Robin Leadbeater
Extreme spectroscopy indeed !

No H alpha and a dip at ~6100A (Si II ? ) A type Ia perhaps ? Do you have the fits file ? I could try it in GELATO

Cheers
Robin

Re: Supernova in NGC 1365

Posted: Mon Oct 29, 2012 11:37 am
by Terry Bohlsen
This is excellent Christian
I will try with essentially the same equipment ASAP but currently have 100% cloud cover. :cry:

Re: Supernova in NGC 1365

Posted: Mon Oct 29, 2012 4:07 pm
by Christian Buil
Terry, good luck (this object is for you if weather is better!)

More info about (extreme, yes) conditions during the observation from Castanet observatory:

Image

All is possible with your spectrograph!

My SN page is updated for download:
http://www.astrosurf.com/buil/supernovae/2012/index.htm

Christian B

Re: Supernova in NGC 1365

Posted: Mon Oct 29, 2012 6:22 pm
by Robin Leadbeater
Hello Christian,

I see it has been clasified as type 1a
http://www.astronomerstelegram.org/?read=4525
I tried your spectrum in GELATO. It consistently classifies it as type 1c pec (similar to 2002ap or 2003jd at maximum +-2 days). It will be interesting to see how much brighter it gets.

Cheers
Robin

Re: Supernova in NGC 1365

Posted: Tue Oct 30, 2012 9:26 am
by Bernard Heathcote
Despite a very hazy sky, but with a high target, I managed to get 7x600s spectra of the NGC1365 SN last night (HJD 2456230.1018) with my 0.28m C11, Lhires+150 grating, 35um slit, Atik314L main camera and Lodestar (+PHD) autoguider. Although I didn't have the time to grab any photometry the SN is brighter. Based on the Ha emission from the main galaxy I measured a 1686 km/s redshift, which is within 1.25% of the 1665 km/s SIMBAD value. GELATO gave a good match (>70%) to a Type ia (thermonuclear), which accords with the pro result. Note that the SN spectra shown below has been redshift corrected (-37A) in order to allow easier comparison with reference spectra.

The galaxy spectra shows strong Ha , Hb amd [OIII] (5007A) emission.

Cheers, Bernard

Re: Supernova in NGC 1365

Posted: Tue Oct 30, 2012 11:04 am
by Terry Bohlsen
Well done Bernard.
Still cloud here but forecast is slightly better for tomorrow but cloud again after that.

Re: Supernova in NGC 1365

Posted: Tue Oct 30, 2012 12:46 pm
by Terry Bohlsen
Amazingly the clouds sort of cleared for a while tonight and I was able to get about 30mins of cloud affected exposure of the SN.
A similar spectra to what Bernard achieved.
_sninngc1365_20121030_492.png
_sninngc1365_20121030_492.png (7.58 KiB) Viewed 9556 times

Re: Supernova in NGC 1365

Posted: Wed Oct 31, 2012 3:39 am
by Christian Buil
Excellent spectra Terry and Bernard !

Here, a reprocessing of my observation (better sky removal, and also binning by a factor 5x of the profile, so I reduce drastically spectral resolution):

Image

My best effort.

Clearly Terry and Bernard your obsertory are in a better place ;)
Continue to observe.

Christian