SUPERNOVA
2011dg IN IC 4523 = PSN J15050910-4330462
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, D. Iturra, and R. Ramirez, 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 17.0) on an unfiltered image taken on
May 18.24 UT with the 0.41-m 'PROMPT 1' telescope
located at Cerro Tololo. The new object (which was
designated PSN J15050910-4330462 when posted on the
Central Bureau's TOCP webpage and is here designated
SN 2011dg based on the spectroscopic report below)
is located at R.A. = 15h05m09s.10 +/- 0".2, Decl.
= -43°30'46".2 +/- 0".2 (equinox 2000.0), which is
about 15".5 west and 12".4 south of the center of
the galaxy IC 4523. Additional CCD magnitudes for
2011dg: 2010 Apr. 13.24, [18.5 (CHASE); 2011 May 7.11,
[17.0 (CHASE); 19.00, 16.4 (CHASE); 22.666, 17.2 (Joseph
Brimacombe, Coral Towers Observatory, Cairns, Australia,
30-cm reflector + STL6K camera + red filter; ten 600-s
stacked images; position end figures 09s.12, 45".9).
Brimacombe's image is posted at the following website
URL: http://www.flickr.com/photos/43846774@N02/5748616071/.
The type-IIP supernova 2010gh also appeared in IC
4523 (cf. CBETs 2372, 2390).
M. Stritzinger, Oskar Klein Centre, Stockholm University,
on behalf of the Millennium Center for Supernova Science,
reports that he obtained a spectrogram on May 29.4
UT of PSN J15050910-4330462 = SN 2011dg with the Gemini-South
telescope (+ GMOS). The spectrum of 2011dg is consistent
with that of a normal type-IIP supernova at about
two weeks past explosion.
NOTE: These 'Central Bureau Electronic
Telegrams' are sometimes superseded by text appearing
later in the printed IAU Circulars.