New Possible Supernova in NGC1365

[lepton3 (Ivan)]

Terry, that is exceptional work. I can see clearly the Iron, Sulphur and Silicon features of a type Ia supernova in that spectrum.

Incredibly impressive.

-Ivan

[LewisM]

Here's my NGC 1365 from about 2 weeks ago:

http://imageshack.us/f/62/fornaxgroupngc1365.png/

[LewisM]

Here is a cropped single 3 minute sub at 100%, pre-SN.

[Greg Bock (Greg Bock)]

Terry, Ken
thanks a bunch guys for posting your info on the spectrum, very informative indeed. Keep it up!

[LewisM]

Taken the first 5 subs (5 mins, with a full moon no less) and it is VERY apparent! YEEHAW!

[cometcatcher (Kevin)]

Looks like about magnitude 13 now very rough estimate.

[Greg Bock (Greg Bock)]

Hi all,
here's an image taken tonight, the new SN is about magnitude 13.3 V.
Bright moonlight created the annoying bckground...

[LewisM]

Best I could do with an ED127 refractor tonight, smack bang in the middle of suburbia with that darned moon!

[Larryp (Laurie)]

Pretty good, Lewis!

[mental4astro (Alexander)]

Lewis, I'll be using your photo as a guide to 1365 from home if I can manage an evening WITHOUT clouds. I should be able to star hop to it incase I can't make out too much of the faint fuzzy. I'll use my 8" dob, and hopefully my 17.5 if the sky looks good. With the Moon about this still shouldn't be a problem. I've seen 1365 from a dark site, and it is stunning, but I haven't tried from home.

[Glenpiper (Bernard)]

Thre are more amateur spectra and comment, including GELATO's 1a type confirmation of this SN, with Terry's and my spectra, in the ARAS forum at http://www.spectro-aras.com/forum/vi....php?f=6&t=465

Cheers,

[mental4astro (Alexander)]

Q. where can I find info on Type I & II supernovae? I don't know the difference between them.

[Merlin66 (Ken)]

Kaler's "Stars and their spectra', 2nd ed, pages 366 -376.
then
Gaposchkin's "The galactic Novae", page 259-285

Executive summary:
Type I - No hydrogen absorption/emmison
Ia - strong SII
Ib - none of the above, but HeI
Ic - lines of light elements ie oxygen and calcium
Type II - Hydrogen lines emmision and/or absorption
All have different light curves
Type Ia - can be found anywhere in the galaxy/ halo (Population II)
Type II -on in the disk (Population I)
See also:
http://en.wikipedia.org/wiki/Supernova
HTH

[Terry B]

From last night.
magnitude
B = 13.50
V = 13.47
R = 13.43
I = 13.54

The image is through a V filter
The spectra is a comparison with a type 1a sn

Cheers

Terry

[cometcatcher (Kevin)]

Wide field shot through a 5" F5 refractor, 15x2 mins.

[Greg Bock (Greg Bock)]

Originally Posted by Terry B

From last night.
magnitude
B = 13.50
V = 13.47
R = 13.43
I = 13.54

The image is through a V filter
The spectra is a comparison with a type 1a sn

Cheers

Terry

Very nice Terry, agrees well with my image above taken 2 days ago.

[JohnG (John)]

Taken at around 0945UT, 01/11/12.

Very windy, 5 x 250 seconds @ -25c with the Takahashi FSQ-106ED at f/5.0. No Flats or Darks, very limited Levels and Curves.

Cheers

[Merlin66 (Ken)]

John,
Well done!
That's a VERY nice image!

[LewisM]

Interesting new astronomer telegram:

ATEL #4535 ATEL #4535

Title: Type-Ia SN 2012fr: no progenitor detected in pre-explosion
HST image to M_V ~ -5.9 mag
Author: Or Graur (Tel-Aviv U., AMNH), Dan Maoz (Tel-Aviv U.)
Queries: maoz@astro.tau.ac.il
Posted: 1 Nov 2012; 22:01 UT
Subjects:Optical, Supernovae

We have analyzed archival Hubble Space Telescope WFPC2 images of NGC 1365
in F606W (~ V band, 560 s total) from 2001. We detect no sources within
a 0.5'' radius of the location of the Type-Ia supernova SN 2012fr (PSN
J03333599-3607377, ATel#4523), as determined by registering the HST images
with images of the SN by Stu Parker and by Ivan Curtis (see http://www.rochesterastronomy.org/snimages),
using two bright stars near the SN. By planting fake point sources at the
location of the SN, we obtain a 2-sigma flux limit of 25.3 mag in F606W.
The Tully-Fisher-based distance modulus of NGC 1365 is 31.16+/-0.35 (Tully
et al. 2009, AJ, 138, 323), and the Galactic extinction in this direction
is A_V=0.056 (Schlafly et al. 2011, ApJ, 737, 103). Barring the possibility
of extinction in the host galaxy, a progenitor or companion of SN 2012fr
was therefore fainter than M_V ~ -5.9 mag, ruling out the presence of supergiants
of such luminosity at the explosion site. An image showing the searched
region of the HST data is at http://www.astro.tau.ac.il/~orgraur/sn2012fr.jpg

[LewisM]

Took another single 300sec sub last night before my camera batteries decided to die (idiot forgot to recharge them!). Less than dark suburbia, as usual.