Electronic Telegram No. 2667
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@eps.harvard.edu (alternate cbat@iau.org)
URL http://www.cbat.eps.harvard.edu/index.html
Prepared using the Tamkin Foundation Computer Network


SUPERNOVA 2011am IN NGC 4219 = PSN J12162600-4319200
     Greg Bock, Windaroo Lakes Observatory, Queensland, reports the discovery
by Stuart Parker (Canterbury, New Zealand) of an apparent supernova on a 40-s
unfiltered CCD image taking using a 35-cm Celestron C14 Schmidt-Cassegrain
telescope (+ SBIG ST10 camera), with the discovery observation tabulated below
(position and magnitude measured by Bock).

 SN       2011 UT         R.A. (2000.0) Decl.      Mag.      Offset
 2011am   Feb. 27.704   12 16 26.00  -43 19 20.0   17.4    11".9 W, 6".5 N

Nothing is visible at this position on Digitized Sky Survey red, blue, or
infrared images (limiting red magnitude > 19).  When posted on the Central
Bureau's TOCP webpage, this variable was designated PSN J12162600-4319200,
and is here designated SN 2011am based on the spectroscopic report below.
Joseph Brimacombe, Cairns, Australia, reports that eight unfiltered 1200-s CCD
images taken remotely on Mar. 3.619 UT with a 40.6-cm RCOS telescope (+ U9000
camera) located at Macedon Ranges Observatory, near Melbourne, Australia,
yield mag 15.9 and position end figures 26s.31, 21".2 for 2011??; his image
is posted at URL http://www.flickr.com/photos/43846774@N02/5495919426/.

     N. Morrell, Las Campanas Observatory; M. Stritzinger, Stockholm
University; and Luis Ho, Carnegie Observatories, report that they obtained a
spectrum (range 340-910 nm) of 2011am on Mar. 5.4 UT with the Magellan II
Clay 6.5-m telescope (+ MagE) at Las Campanas Observatory.  The spectrum of
2011am is that of a young, normal type-Ib supernova, most similar to SN 2007Y
(Stritzinger et al. 2009, Ap.J. 696, 713) at about a week before maximum.
Adopting for NGC 4219 a recession velocity of 1989 km/s (Koribalski et al.
2004, A.J. 128, 16), the minimum of the absorption lines of Ca II H and K,
He I 587.6-nm, and the Ca II infrared triplet appear to be blueshifted by
roughly 15000 km/s.  A similar anaylsis yields an expansion velocity of 12500
km/s for Fe II 516.9-nm.  The medium-resolution spectrum also exhibits strong
Ca II H and K and Na I D interstellar absorption at the radial velocity of the
host galaxy.  Morrell also sends position end figures 26s.6, 21".0 for 2011am.


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

                         (C) Copyright 2011 CBAT
2011 March 6                     (CBET 2667)              Daniel W. E. Green