[IAUC] CBET 2713: 20110505 : SUPERNOVA 2011cd IN MCG -02-52-11 = PSN J20321290-0843470

[quai en eps.harvard.edu]

                                                  Electronic Telegram No. 2713
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 2011cd IN MCG -02-52-11 = PSN J20321290-0843470
     G. Pignata and M. Cifuentes, Universidad Andres Bello; J. Maza, M. Hamuy,
R. Antezana, L. Gonzalez, R. Cartier, F. Forster, S. Silva, F. Carrasco, P.
Sanchez, C. Hervias, and D. Iturra, Universidad de Chile; C. Farias,
Pontificia Universidad Catolica de Chile; B. Conuel, Wesleyan University; G.
Folatelli, IPMU, University of Tokyo; and D. Reichart, K. Ivarsen, J. Haislip,
A. Crain, D. Foster, M. Nysewander, and A. LaCluyze, University of North
Carolina at Chapel Hill, on behalf of the CHASE project (which is part of the
Millennium Center for Supernova Science collaboration), report the discovery
of an apparent supernova (mag approximately 17.7 +/- 0.4) on an unfiltered
image taken on Apr. 14.34 UT with the 0.41-m 'PROMPT 3' telescope located at
Cerro Tololo.  The new object (which was designated PSN J20321290-0843470
when posted at the Central Bureau's TOCP webpage and is here designated SN
2011cd based on the spectroscopic report below) is located at R.A. =
20h32m12s.96 +/- 0".2, Decl. = -8d43'47".1 +/- 0".2 (equinox 2000.0), which
is about 2".7 east and 14".3 north of center of the galaxy MCG -02-52-11 (=
PGC 64907).  Additional CCD magnitudes for 2011cd (unfiltered unless otherwise
noted):  2009 Sept. 25.03, [18.5 (CHASE/PROMPT); 2010 Mar. 28.38, [18.5
(CHASE/PROMPT); 2011 Apr. 16.36, 17.4 (CHASE/PROMPT); 20.470, 18.9 (Joseph
Brimacombe, Cairns, Australia; remotely using a 51-cm RCOS telescope + STL11K
camera at the New Mexico Skies Observatory near Mayhill, NM, U.S.A.; position
end figures 12s.96, 46".3); 22.779, 18.7 (Brimacombe; red filter; position end
figures 12s.95, 46".9).  Brimacombe's Apr. 20 image is posted at website URL
http://www.flickr.com/photos/43846774@N02/5639435949/; his Apr. 22 image is
posted at http://www.flickr.com/photos/43846774@N02/5645086959/.

     M. Stritzinger, A. Jerkstrand, J. Sollerman, M. Ergon; Oskar Klein Centre,
Stockholm University; and R. J. Foley; Harvard-Smithsonian Center for
Astrophysics, on the behalf of the Millenium Center for Supernova Studies
(Universidad de Chile), report that they obtained a spectrogram on Apr. 28.2
UT of 2011cd with the Gemini-South telescope (+ GMOS).  The spectrum contains
a rich number of emission lines including, among others:  numerous Fe II lines
between 400 and 550 nm; Mg I] at 451 nm; Na I D, possibly blended with He I
588-nm; [O I] at 558 and 630/636 nm; H_alpha; Fe II at 715 nm; [Ca I] at 730
nm; O I at 777 nm; a prevalent emission feature due to the Ca II near-infrared
triplet; and a tentative identification of He I at 707 nm.  All emission
features except the Ca lines show strong blueshifts, with H_alpha showing the
most pronounced blueshift of approximately 3500 km/s.  The spectrum is
consistent with that of a type-II supernova at late phases.


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

                         (C) Copyright 2011 CBAT
2011 May 5                       (CBET 2713)              Daniel W. E. Green