Electronic Telegram No. 2739 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 2011dc L. Tomasella, P. Ochner, S. Valenti, and S. Benetti, Istituto Nazionale di Astrofisica, Osservatorio Astronomico di Padova; and A. Pastorello, Dipartimento di Astronomia, Universita di Padova, on behalf of a larger collaboration, report that a spectrogram (range 390-810 nm; resolution 2.2 nm) of SN 2011dc (cf. CBET 2726), obtained on June 7.00 UT with the Ekar-Copernicus 1.82-m telescope (+ AFOSC), confirms that it is a type-I supernova. The spectrum shows strong features of helium at 587.6 and 667.8 nm, typical of type-Ib supernovae after maximum. Cross-correlation of the observed spectrum with a library of supernova spectra using the "GELATO" code (Harutyunyan et al. 2008, A.Ap. 488, 383, available at https://gelato.tng.iac.es/login.cgi) shows that SN 2011dc is similar to 1999dn at one week after maximum (Benetti et al. 2011, MNRAS 411, 2726). NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2011 CBAT 2011 June 10 (CBET 2739) Daniel W. E. Green