2012CBET.3263....2T

L. Tomasella, M. Turatto, Benetti, A. Pastorello, P. Ochner, E. Cappellaro, Osservatorio Astronomico di Padova, Istituto Nazionale di Astrofisica, report that a spectrogram of PSN J10433405+2453290 = SN 2012fh, obtained on Oct. 20.13 UT with the Asiago 1.82-m Copernico Telescope (+ AFOSC; range 350-820 nm; resolution 1.3 nm), shows very strong emission lines of [O I], [Ca II], O I, [Fe II], Mg I], and Na I D line, the latter with a residual P-Cyg absorption. These features are typical of supernovae with evolved stripped envelopes (type-Ib/c and type-IIb supernovae). In particular, adopting for the host galaxy (NGC 3344) the redshift z = 0.001935 (Epinat et al. 2008, MNRAS 388, 500; via NED), the best fit with the GELATO tool (Harutyuyan et al. 2008, A.Ap. 488, 383) is obtained with the type-Ic supernova 2007gr at about about 130 days past maximum. The [O I] feature has the characteristic double peak shown by other objects (e.g., SN 2008ax), interpreted by some authors as indication of asphericity of the explosion (e.g., Maeda et al. 2008, Science Express 319, 1220; Taubenberger et al. 2009, MNRAS 371, 1459). The [Ca II]/[O I] ratio, sensitive to the core mass (and hence to the main-sequence mass of the progenitor), is 0.23; this seems to indicate a massive progenitor.