Classification of CSS121015:004244+132827
ATel #4512; L. Tomasella, S. Benetti, A. Pastorello, E. Cappellaro, M. Turatto (INAF - Osservatorio Astronomico di Padova), A. Harutyunyan (Telescopio Nazionale Galileo)
on 23 Oct 2012; 15:54 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Stefano Benetti (firstname.lastname@example.org)
Subjects: Optical, Supernovae, Transient
Referred to by ATel #: 6288
We report that spectrograms of CSS121015:004244+132827=2012XX obtained on Oct. 19.89 UT and on Oct. 22.81 with the Asiago 1.82-m Copernico Telescope (+ AFOSC; range 350-820 nm; resolution 1.3 nm), and on Oct. 22.88 UT with the Telescopio Nazionale Galileo (+ LRS, range 320-800 nm; resolution 1.1 nm) show it to have a very blue, featureless continuum. This agrees with the description of the spectrum given by Drake et al. 2012, ATel#4498. A narrow absorption attributed to the host galaxy Mg II doublet (2796-2803A), and the detection of very weak Balmer emission lines (Hbeta, Hgamma, Hdelta) allow us to estimate the host galaxy redshift to be z=0.286. Adopting this redshift value, the resulting absolute magnitude of the transient would be about -22.5, making it a luminous member of the class of ultra-bright, stripped envelope events similar to SN 2010gx (Pastorello et al. 2010, ApJ, 724L, 16; Quimby et al. 2011, Nature, 474, 487). An extensive monitoring campaign is in progress.