[IAUC] CBET 2670: 20110310 : SUPERNOVA 2011ap IN IC 1277 = PSN J18102840+3100342

Mie Sep 14 16:19:02 ART 2011

                                                  Electronic Telegram No. 2670
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
CBAT Director:  Daniel W. E. Green; Hoffman Lab 209; Harvard University;
 20 Oxford St.; Cambridge, MA  02138; U.S.A.
e-mail:  cbatiau en eps.harvard.edu (alternate cbat en iau.org)
URL http://www.cbat.eps.harvard.edu/index.html
Prepared using the Tamkin Foundation Computer Network


SUPERNOVA 2011ap IN IC 1277 = PSN J18102840+3100342
     S. Nakano, Sumoto, Japan, reports the discovery by Koichi Itagaki
(Teppo-cho, Yamagata, Japan) of an apparent supernova (mag 18.3) on a 15-s
unfiltered CCD frame (limiting magnitude 19.5) taken on Feb. 21.856 UT using a
0.60-m f/5.7 reflector (+ BITRAN camera).  The new object is located 14" east
and 23" north of the center of IC 1277.  Nothing is visible at this position
on the Digitized Sky Survey (limiting mag about 20; no bandpass or plate type
provided) on on Itagaki's image from 2006 Aug. 15.52 (limiting mag 20.5).  The
variable was designated PSN J18102840+3100342 when posted at the Central
Bureau's TOCP webpage and is here designated 2011ap based on the spectroscopic
report below.  Reported astrometry and unfiltered CCD magnitudes for 2011ap:

  2011 UT          R.A. (2000.0) Decl.       Mag.    Observer
  Feb. 16.234    18 10 28.41  +31 00 34.3    18.5    Boles
       18.547                                18.5    Boles
       21.856    18 10 28.40  +31 00 34.2    18.3    Itagaki
       22.446    18 10 28.37  +31 00 34.1    17.6    Brimacombe
       22.45     18 10 28.35  +31 00 33.5    18.3    Koff
       22.469    18 10 28.36  +31 00 33.9    18.0    Yusa
       22.730    18 10 28.35  +31 00 34.1    17.9    Kadota
       22.841                                18.1    Itagaki
       23.508                                16.8    Brimacombe
       25.551                                16.4      "
  Mar.  1.504                                15.9      "
        6.505                                16.0      "

T. Boles (Coddenham, England).  0.35-m reflector.  Independent discovery
  (reported after Itagaki's discovery).  Offset approximately 14".5 east
  and 22".8 north of the center of IC 1277.
J. Brimacombe (Cairns, Australia).  Remotely using a 51-cm RCOS telescope at
  New Mexico Skies Observatory near Mayhill, NM, U.S.A.  Magnitude and
  position for Feb. 22 image measured by Boles (otherwise measured by
  Brimacombe).  Brightness on Feb. 23 was 0.2 mag brighter than on Feb. 22.
  Images posted at http://www.flickr.com/photos/43846774@N02/5472457359/,
  http://www.flickr.com/photos/43846774@N02/5477943145/, and
  http://www.flickr.com/photos/43846774@N02/5504029518/.
Ken-ichi Kadota (Ageo, Japan).  0.25-m f/5 reflector + SBIG ST-9E camera
  (limiting mag 18.9); offset 13".5 east, 22".1 north.  Communicated by
  Nakano.  His image is posted at the following website URL:
  http://members.jcom.home.ne.jp/kenic-k/image/PSNinIC1277-20110222.jpg.
T. Yusa (Osaki, Japan).  remotely with a 0.25-m f/3.4 hyperbolic astrograph
  + SBIG ST-10XME CCD camera at the RAS Observatory near Mayhill, NM, U.S.A.
  Three 120-s exposures (limiting mag 19.5).  Offset 13".1 east, 22".6 south.
  Image posted at http://space.geocities.jp/yusastar77/PSNJ181028403100342.htm.
R. A. Koff (Bennett, CO, U.S.A.).  Twenty-five co-added 60-s images.

     Boles adds that Digitized Sky Survey plates (limiting red mag 20.5 and
limiting blue mag 21.0) show a star-sized "hot spot" fainter than mag 20.0,
and that nothing is visible at the position of 2011ap in Boles's archival
images to limiting mag 19.5 taken over the last ten years.  Itagaki has posted
his discovery image at http://www.k-itagaki.jp/images/psn1277.jpg; his second-
night image is posted at http://www.k-itagaki.jp/images/ic1277-2.jpg.  The
type-Ia supernova 2006gz also appeared in IC 1277 (cf. IAUC 8754).

     G. H. Marion, Harvard-Smithsonian Center for Astrophysics (CfA), on behalf
of the CfA Supernova Group, report that a spectrum (range 340-740 nm) of
PSN J18102840+310034 = 2011ap was obtained on Mar. 8 UT by P. Berlind with the
F. L. Whipple Observatory 1.5-m telescope (+ FAST).  Cross-correlation with a
library of supernova spectra using the "Supernova Identification" code (SNID;
Blondin and Tonry 2007, Ap.J. 666, 1024) shows that 2011ap is a type-IIn
supernova a few days after maximum light.


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2011 CBAT
2011 March 10                    (CBET 2670)              Daniel W. E. Green