(IAAC) BRIGHT supernova in lovely barred spiral NGC 2403 in Camelopardalis

Tue Aug 3 16:07:03 EDT 2004

A magnitude 11 supernova in another Local Group galaxy is a rare
treat. According to one of the forwards below, it has been seen
in a 3.5" scope - presumably from a dark site, but still... ! :)

This gorgeous, loose, well-known SAB galaxy may be considered
tricky to find, due to a lack of bright landmark stars in Cam.

It definitely requires decent charts and some starhopping, and
the nearest starting points are either mag 3.5 Omicron UMa (aka
"Muscida") some 8 degrees to the SE, or the pretty orange star
Pi UMa, mag 4.5, which lies about about 7 degrees to the E.

Once the hop is over, though, NGC2403 is well worth it - with
or without the excitement of a mag 11 supernova inside, it is
a very pretty sight in even moderate scopes, from a dark site:
 http://www.visualdeepsky.org/logs/msg01014.html
 http://www.visualdeepsky.org/logs/msg02044.html
 http://www.visualdeepsky.org/logs/msg03028.html

PS: Here are emails from various sources, with supplementary
details on this extraordinary extragalactic event! The CBAT's
initial notification about the SN is at the very bottom.

Clear skies, and happy SN hunting!
Lew Gramer

-----Original thread from amastro forum-----
Message: 1
Sent: Sun, 1 Aug 2004 10:28:21 -0700 (MST)
From: Brian Skiff <brian...>
Subject: NGC 2403 supernova

 A bright supernova has been reported in the nearby galaxy NGC 2403
by K. Itagaki in Japan.  Location is:  7 37 17.0 +65 35 58 (J2000),
which is about 160" east and 10" north of the nucleus.  It is
reported as mag 11.2.

\Brian

________________________________________________________________________
Message: 2
Sent: Sun, 1 Aug 2004 14:34:42 -0700
From: Kent Wallace

Brian,

The position for this supernova is very close to a cluster of stars
in NGC2403 called [L99] n2403-2866 in SIMBAD at (2000.0) 07 37 16.93
+65 35 57.7

Thanks for the notification.

Kent

________________________________________________________________________
Message: 3
Sent: Sun, 1 Aug 2004 14:54:51 -0700 (MST)
From: Brian Skiff

>>  The position for this supernova is very close to a cluster of stars in
>>  NGC2403 called [L99] n2403-2866 in SIMBAD...

     This suggests the progenitor is a massive star, so thus a
less-luminous type II supernova rather than type I (white dwarf
progenitor). Presumably someone will publish a spectrum within
a day or two---if  anyone can get far enough over in hour-angle!

\Brian

-----Original Message from a local astronomy Club-----
Sent: Tuesday, August 03, 2004 10:06 AM
From: gaac On Behalf Of Michael Deneen
Subject: Re: GAAC Astro: Bright Supernova in NGC 2403 (fwd)

Thanks for the heads-up on the supernova, Dan.

NGC 2403 is also known as Caldwell 7, so a telrad chart for this galaxy can
be found here:

http://www.utahskies.org/deepsky/caldwell/charts/caldwellTelradFrameSet.html

It's part of the same [very wide-spread] group as M81 & M82.

MPD

-----Original Message-----
Sent: Tuesday, August 03, 2004 10:06 AM
From: Dan Rehner

	Hi all,  this is from a friend of mine in MD.

      Dan Rehner

           * * * * * Bright Sunpernova 2004dj in NGC 2403 * * * * *

 A supernova of unknown type was recently discovered in the galaxy NGC 2403
in Camelopardus. When found it was 11.2 magnitude, and estimates yesterday
by variable star observers put it at ~11.6 V (Bouma) according to IAUC 8377.

 This should be bright enough to see visually in a good 4-inch telescope.
The position of the SN is: RA = 7h37m17s.02, Decl. = +65o35'57".8 (equinox
2000), roughly 160" east and 10" north of the nucleus of NGC 2403.

 A good picture of the galaxy before the SN event and after are at:
http://www.rochesterastronomy.org/snimages/reference/n2403.jpg
http://www.rochesterastronomy.org/sn2004/n2403s1.jpg
  [URLs corrected as per followup post...]
  [Thanks to John Wood of GSFC for alerting me of my error. -GWG]

Good Observing,
GW Gliba

-----Original Message from deepsky email list-----
Sent: Tue, 03 Aug 2004 10:40:58 -0000
From: Dave Mitsky <...>
Subject: A Bright Supernova in NGC 2403

An eleventh magnitude supernova was discovered on 2004/07/31.76 by
Koichi Itagaki.  SN 2004dj is located approximately 160" east and 10"
north of the nucleus of NGC 2403, an 8.5 magnitude spiral galaxy in
Camelopardalis, at 7h37m17s, +65d35'58".  This supernova is unusually
bright and has already been observed with only 90mm of aperture.

See http://www.rochesterastronomy.org/sn2004/n2403s1.jpg for an image
of SN 2004dj.

Dave Mitsky

-----Original message from a fellow deep-sky observer-----
Sent: Monday, August 02, 2004 7:22 PM
From: Alan Goldstein
To: Many individual recipients

Forwarded to me by an astronomer/friend of mine.

Alan

Electronic Telegram No. 74
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
M.S. 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS at CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
CBAT at CFA.HARVARD.EDU (science)
URL http://cfa-www.harvard.edu/iau/cbat.html

SUPERNOVA 2004dj IN NGC 2403
     S. Nakano, Sumoto, Japan, reports the discovery by K. Itagaki,
Teppo-cho, Yamagata, Japan, of a bright supernova on at least ten CCD frames
taken around July 31.76 UT using a 0.60-m f/7 reflector.  The object is
located at R.A. = 7h37m17s.02, Decl. = +65o35'57".8 (equinox 2000.0),
which is roughly 160" east and 10" north of the nucleus of NGC 2403.
The unfiltered (roughly V) mag was 11.2.  Itagaki confirmed the object on
Aug. 1.45, when it was estimated at mag 11.3.  Nothing was visible at the
object's location on Itagaki's numerous earlier CCD frames; specifically,
it was not present to limiting mag 18.5 on 2002 Sept. 19 and Oct. 11.

NOTE: These 'Central Bureau Electronic Telegrams' are intended to
      be preliminary announcements of items that later appear in the
      formal IAU Circulars.  Citations should normally be made to IAUCs
      rather than to CBETs.

                         (C) Copyright 2004 CBAT
2004 August 1                     (CBET 74)               Brian G. Marsden