[IAUC] CBET 2934: 20111204 : SUPERNOVA 2011ir IN UGC 6771 = PSN J11480032+0429471

Dom Dic 4 02:37:30 ART 2011

                                                  Electronic Telegram No. 2934
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)
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Prepared using the Tamkin Foundation Computer Network


SUPERNOVA 2011ir IN UGC 6771 = PSN J11480032+0429471
     Isao Endoh, National Astronomical Observatory of Japan, reports the
discovery by Shigeru Furuyama (Tone-machi, Kitasoma-gun, Ibaraki-ken, Japan)
of an apparent supernova (mag 16.1) on a 20-s CCD exposure (limiting mag 17.5)
taken on Nov. 21.813 UT with a 25-cm f/4.8 reflector (+ ST-9E camera).  The
new object is located at R.A. = 11h48m00s.32, Decl. = +4d29'47".1 (equinox
2000.0; UCAC3 reference stars; Astrometrica software), which is 1".2 east and
29".9 north of the center of UGC 6771.  Nothing is visible at this position
on the Digitized Sky Survey.  The variable was designated PSN
J11480032+0429471 when it was posted at the Central Bureau's TOCP webpage and
is here designated SN 2011ir based on the spectroscopic confirmation reported
below.  Additional CCD magnitudes for 2011ir (from unfiltered images unless
otherwise noted):  1991 Jan. 23, [18.8 (DSS red plate; via Toru Yusa); Nov.
23.473, 16.6 (Yusa; remotely using a 0.25-m f/3.4 hyperbolic astrograph + SBIG
ST-10XME camera at the RAS Observatory near Mayhill, NM, U.S.A.; three stacked
120-s exposures; limiting mag 18.5; position end figures 00s.29, 48".4; offset
1".3 east, 31".6 north; center of UGC 6771 at position end figures 00s.20,
16".8; USNO-B1.0 reference stars; communicated by S. Nakano); 23.797, 16.5 (T.
Noguchi, Katori, Chiba-ken, Japan; 0.23-m f/6.3 Schmidt Cassegrain + BITRAN
BT-11E camera; limiting mag 18.0; position end figures 00s.33, 47".0; offset
1".2 east, 29".5 north; center of UGC 6771 at position end figures 00s.25,
17".5; UCAC3 reference stars; communicated by Nakano); 24.496, 16.2 (Joseph
Brimacombe, Cairns, Australia; 51-cm RCOS telescope + STL11K camera + luminance
filter; position end figures 00s.33, 47".0; image posted at website URL
http://www.flickr.com/photos/43846774@N02/6398340787/); 25.168, 16.0 (Federica
Luppi and Luca Buzzi, Varese, Italy; 0.38-m f/6.8 reflector; position end
figures 00s.31, 47".2; reference stars from CMC-14 catalogue; image posted at
URL http://www.astrogeo.va.it/pub/TOCP/PSN_U6771.jpg).  Yusa's image is posted
at website URL http://space.geocities.jp/yusastar77/PSNinUGC6771_111101.htm,
and Noguchi's image at http://park8.wakwak.com/~ngc/images/PSN_in_UGC6771.jpg.

     L. Tomasella, A. Pastorello, S. Valenti, and S. Benetti, Istituto
Nazionale di Astrofisica, Osservatorio Astronomico di Padova, on behalf of a
larger collaboration, report that a spectrogram of PSN J11480032+0429471 =
SN 2011ir, obtained on Nov. 28.16 UT with the Asiago 1.82-m Copernico Telescope
(+ AFOSC; range 350-820 nm, resolution 2.4 nm), shows it to be a type-II
supernova.  The best fit to this spectrum found by GELATO (Harutyunyan et al.
2008, A.Ap. 488, 383; available at URL https://gelato.tng.iac.es/login.cgi)
suggests that 2011ir is similar to SN 1998S (Lentz et al 2001, Ap.J. 547, 406)
about one week after maximum light, adopting for the host galaxy a redshift of
z = 0.01989 (de Vaucouleurs et al. 1991, RC3 catalogue, via NED).


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

                         (C) Copyright 2011 CBAT
2011 December 4                  (CBET 2934)              Daniel W. E. Green