SN 2011ia in mgc+11-12-023 - 18 novembre 2011

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SN 2011ia (A.R. 09 45 03.55, Dec. +64 15 36.6) scoperta il 18 novembre 2011 nella galassia MCG+11-12-023 (offset 2E 16N), magnitudine 16.2.

SN scoperta da F. Ciabattari ed E. Mazzoni con il telescopio Newton da 50cm dell'Osservatorio di Monte Agliale (Lucca).

                                                  Electronic Telegram No. 2910
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.
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SUPERNOVA 2011ia IN MCG +11-12-23 = PSN J09450355+6415366
F. Ciabattari, S. Donati, E. Mazzoni, G. Petroni, and M. Rossi, Borgo a
Mozzano, Italy, report their discovery of an apparent supernova (mag 16.2) on
unfiltered CCD images obtained on Nov. 18.21 and 19.01 UT with a 0.5-m
Newtonian reflector in the course of the Italian Supernovae Search Project.
The new object is located at R.A. = 9h45m03s.55, Decl. = +64d15'36".6 (equinox
2000.0; astrometry with respect to UCAC-2 stars) which is 2" east and 16"
north of the center of the galaxy MCG +11-12-23 (= PGC 27923). The variable
was designated PSN J09450355+6415366 when it was posted at the Central Bureau's
TOCP webpage and is here designated SN 2011ia based on the spectroscopic
confirmation reported below. Additional magnitudes for 2011ia (via unfiltered
CCD unless noted otherwise): 1989 Dec. 23, [20.3 (Palomar Sky Survey, F plate;
via Ciabattari); 1995 Mar. 26, [20.3 (Palomar Sky Survey, J plate; via
Ciabattari); Nov. 19.117, 15.1 (Federica Luppi and Luca Buzzi, Varese, Italy;
position end figures 03s.40, 35".0; reference stars from PPMXL catalogue;
image posted at URL http://www.astrogeo.va.it/pub/TOCP/PSN_G11-12-23.jpg);
19.316, 15.3 (R. A. Koff, Bennett, CO, USA; Meade 0.25-m f/10 reflector +
Apogee AP-47p camera; limiting magnitude 18.4; position end figures 03s.36,
35".5; UCAC3 reference stars); 20.512, 15.6 (Joseph Brimacombe, Cairns,
Australia; luminance filter; position end figures 03s.47, 35".0; image posted
at website URL http://www.flickr.com/photos/43846774@N02/6372205161/).

S. Valenti, A. Pastorello, S. Benetti, L. Tomasella, F. Bufano, and P.
Ochner, Istituto Nazionale di Astrofisica, Osservatorio Astronomico di Padova,
on behalf of a larger collaboration, report that a spectrogram of PSN
J09450355+6415366 = SN 2011ia, obtained on Nov. 20.08 UT with the 1.82-m
Copernico Telescope (+ AFOSC; range 340-790 nm, resolution 2.2 nm), suggests
that it is a type-Ia supernova. Cross-correlation with a library of supernova
spectra through the "Supernova Identification" code (SNID; Blondin and Tonry
2007, Ap.J. 666, 1024) indicates that 2011ia is a type-Ia supernova about 9
days before its B-band maximum. Adopting a redshift z = 0.019, from the
position of the minimum of the Si II 635.5-nm line, a velocity for the ejected
material of about 11500 km/s is derived.


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

(C) Copyright 2011 CBAT
2011 November 22 (CBET 2910) Daniel W. E. Green