SN 2013bm (A.R. 10 48 26.57, Dec. +38 24 07.9), scoperta il 16 aprile 2013 nella galassia ugc 5910 (offset 16W 19N), magnitudine 17.9, tipo II (Atel 4989).
SN scoperta da Fabrizio Ciabattari e Emiliano Mazzoni con il telescopio Newton da 50cm dell'Osservatorio di Monte Agliale (Lucca).
Electronic Telegram No. 3487 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: Questo indirizzo e-mail è protetto dallo spam bot. Abilita Javascript per vederlo. (alternate Questo indirizzo e-mail è protetto dallo spam bot. Abilita Javascript per vederlo. ) URL http://www.cbat.eps.harvard.edu/index.html Prepared using the Tamkin Foundation Computer Network SUPERNOVA 2013bm IN UGC 5910 = PSN J10482657+3824079 F. Ciabattari and E. Mazzoni, Borgo a Mozzano, Italy, report the discovery of a possible supernova (mag 17.9) on unfiltered CCD images (limiting magnitude 19.5) obtained on Apr. 16.81 and 17.89 UT with a 0.5-m Newtonian telescope in the course of the Italian Supernovae Search Project; the new object is located at R.A. = 10h48m26s.57, Decl. = +38d24'07".9 (equinox 2000.0; astrometry with respect to UCAC-2 stars), which is 16" west and 19" north of the center of the galaxy UGC 5910. Nothing is visible at this position on digitized plates of the Palomar Sky Survey from 1998 May 16 (F plate; limiting magnitude 20.3) and 1991 Feb. 8 (J plate; limiting mag 20.3). The variable was designated PSN J10482657+3824079 when it was posted at the Central Bureau's TOCP webpage and is here designated SN 2013bm based on the spectroscopic confirmation reported below. Additional CCD magnitudes for 2013bm: 2013 Jan. 12, [19.2 (Ciabattari); Apr. 18.058, 17.7 (Federica Luppi and Luca Buzzi, Varese, Italy; 0.38-m f/6.8 reflector; position end figures 26s.60, 07".5; reference stars from CMC-14 catalogue; image posted at website URL http://www.astrogeo.va.it/pub/TOCP/PSN_U5910.jpg); 18.480, 18.8 (Joseph Brimacombe, Cairns, Australia; 41-cm CDK telescope + infrared filter; position end figures 26s.54, 08".2; image posted at the following website URL: http://www.flickr.com/photos/43846774@N02/8662138755/). L. Tomasella, S. Benetti, A. Pastorello, E. Cappellaro, M. Turatto, and P. Ochner, Osservatorio Astronomico di Padova, Istituto Nazionale di Astrofisica, report that a spectrogram (range 340-820 nm; resolution 1.3 nm), obtained on Apr. 17.94 UT with the Asiago 1.82-m Copernico Telescope (+ AFOSC) shows that PSN J10482657+3824079 = SN 2013bm is a young type-II supernova. The spectrum of 2013bm shows a blue continuum with a black-body temperature of about 10800 K. Emission Balmer and He I 587.6-nm lines are recovered at the recession velocity of the host galaxy (UGC 5910), 7661 km/s (from SDSS data release 5, 2006; via NED). The Asiago classification spectra are posted at website URL http://graspa.oapd.inaf.it. Classification was made via GELATO (Harutyunyan et al. 2008, A.Ap. 488, 383) and SNID (Blondin and Tonry 2007, Ap.J. 666, 1024). NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2013 CBAT 2013 April 23 (CBET 3487) Daniel W. E. Green