Electronic Telegram No. 3282 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 2012fw IN ESO 235-G37 = PSN J21015899-4816259 A. Klotz, Institut de Recherche en Astrophysique et Planetologie, on behalf of the TAROT Collaboration, reports the discovery of an apparent supernova (mag about 15.3) on public images taken on Aug. 19.122 UT by the 0.25-m robotic telescope TAROT at the La Silla observatory, Chile. The new object is located approximately at R.A. = 21h01m58s.99, Decl. = -48o16'25".9 (equinox 2000.0), which is 7" west and 2" north of the nucleus of ESO 235-G37. The variable was designated PSN J21015899-4816259 when it was posted at the Central Bureau's TOCP webpage and is here designated SN 2012fw based on the spectroscopic confirmation reported below. Additional CCD magnitudes for 2012fw: Aug. 7.133, [18.6 (Klotz); 10.313, 16.5 (Klotz; pre-discovery); 23.517, 16.3 (Joseph Brimacombe, Cairns, Australia; infrared filter; wavelength > 700 nm; position end figures 58s.97, 26".8; image posted at website URL http://www.flickr.com/photos/43846774@N02/7848777388/). Klotz writes that spectroscopy of 2012fw was obtained by F. Colas (Institut de Mecanique Celeste et de Calcul des Ephemerides, Paris) with A. Peyrot and J. P. Teng (Association de Gestion de l'Observatoire Reunionnais d'Astronomie, Les Makes, Reunion island), using the 60-cm telescope (+ grating filter with low dispersion of 4.8 nm/pixel) at Les Makes, Reunion island on Aug. 21.6; comparison with spectra provided by C. Buil at URL http://www.astrosurf.com/buil/supernovae/2011/index.htm suggests similarity to the type-Ia supernova 2011fe at five days before maximum when redshifted to z = 0.0186 (the redshift of the presumed host galaxy, ESO 235-G37), with Si II lines being identified. Additional information from Klotz was posted at URL http://cador.obs-hp.fr/sn_tarot/PSN_J21015899-4816259/. L. Chomiuk and J. Strader, Michigan State University, report that a spectrogram of PSN J21015899-4816259 = SN 2012fw, obtained on Aug. 22.1 UT with the SOAR 4.1-m Telescope (+ GHTS; range 500-900 nm; resolution 1.1 nm) is consistent with a normal type-Ia supernova. Adopting for the host galaxy (ESO 235-37) a redshift z = 0.0186 (Jones et al. 2009, MNRAS 399, 683; via NED), a comparison with a library of supernova spectra via GELATO (Harutyuyan et al. 2008, A.Ap. 488, 383) suggests that 2012fw is a few days before maximum. C. Inserra, S. J. Smartt, M. Fraser, D. Young, and K. Smith, Queen's University, Belfast; F. Cellier-Holzem and P. El-Hage, Laboratoire de Physique Nucleaire et de Hautes Energies, Paris; Y.-C. Pan, University of Oxford; M. Sullivan, University of Southampton; I. Arcavi, A. Gal-Yam, and O. Yaron, Wiezmann Institute of Science; S. Benetti, A. Pastorello, and S. Valenti, Istituto Nazionale di Astrofisica, Padova; and S. Taubenberger, A. Sternberg, and S. Benitez-Herrera, Max-Planck-Institute fuer Astrophysik, Garching, on behalf of the PESSTO collaboration (see Valenti et al., posted at website URL http://www.astronomerstelegram.org/?read=4037), report that optical spectroscopy (range 360-910 nm), obtained on Aug. 26 with the New Technology Telescope (+ EFOSC2), show that PSN J21015899-4816259 = SN 2012fw is a type-Ia supernova at redshift z = 0.010; the best fit is to the spectrum of SN 2002ck at maximum light, within a few days of the explosion. PESSTO classification spectra can be obtained at website URL http://www.pessto.org/; classification is made via SNID (Blondin and Tonry 2007, Ap.J. 666, 1024) and GELATO (Harutyunyan et al. 2008, A.Ap. 488, 383). NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2012 CBAT 2012 November 1 (CBET 3282) Daniel W. E. Green