2010CBET.2226....1K

Further to CBET 2214, E. Kankare, Nordic Optical Telescope and Queen's University, Belfast (QUB); A. Pastorello and S. Valenti, QUB; S. Mattila, Tuorla Observatory and QUB; R. Chornock, R. Foley, A. Rest, and G. Narayan, Harvard-Smithsonian Center for Astrophysics (CfA); M. Huber, Johns Hopkins University (JHU); D. Young, K. Smith, and S. Smartt, QUB; J. Tonry and P. A. Price, Institute for Astronomy, University of Hawaii; C. Stubbs, CfA; A. Riess, JHU; W. M. Wood-Vasey, University of Pittsburgh; and E. Berger, CfA, report the discovery of an additional six spectroscopically-confirmed supernovae in the Pan-STARRS1 (PS1) Medium Deep Survey. Spectroscopic classifications were obtained using low-resolution spectra obtained with the Nordic Optical Telescope (+ ALFOSC; range 320-910 nm) on Jan. 21-22 for 2010bb (PS1-1000018), 2010bd (PS1-1000017), and 2010be (PS1-1000021), on Feb. 6 for 2010bc (PS1-1000032), and on Mar. 8 for 2010bf (PS1-1000034) and 2010bg (PS1-1000033). The discovery dates and magnitudes at that time are tabulated below.

---------------------------------------------------------------------------— SN 2010 UT R.A. (2000.0) Decl. Mag. Offset z ---------------------------------------------------------------------------— 2010bb Jan. 16.6 10 44 38.217 +57 48 40.08 20.4 0".1 W 0.118 2010bc Jan. 16.6 10 48 07.057 +56 51 00.44 22.5 0".1 E, 0".4 S 0.244 2010bd Jan. 16.6 12 19 37.532 +46 01 55.98 22.7 1".0 W, 1".0 S 0.057 2010be Jan. 19.2 2 19 46.550 -03 12 10.51 20.2 0".1 E, 0".2 S 0.183 2010bf Feb. 24.4 10 48 15.786 +57 24 19.47 20.2 0".5 N 0.074 2010bg Feb. 24.5 10 57 41.253 +57 36 47.90 20.4 0".2 W, 0".4 S 0.081 ---------------------------------------------------------------------------—

Additional magnitudes: 2010bc, Jan. 17.5, 22.1; 2010bd, Jan. 13.6, 22.1; 2010bg, Feb. 25.5, 20.1. The redshifts of 2010bb and 2010be were determined from the host galaxy Ca II H and K and Na I D interstellar absorption lines, and the redshift for 2010bf from the narrow emission lines of the host galaxy. For 2010bc, a redshift of 0.244 was determined from host- galaxy emission lines using a spectrum obtained on Mar. 13 using GMOS on the Gemini-North telescope (P.I. Berger). The redshifts for 2010bd and 2010bg are the spectroscopic redshifts of their host galaxies (SDSS J121937.40+460156.8 and SDSS J105741.30+573648.4). According to the relation of Turatto et al. (2002, http://lanl.arxiv.org/abs/astro-ph/0211219), the Na I D lines indicate a reddening of E(B-V) around 0.39 and 0.43 for 2010bb and 2010be, respectively; comparison of their de-reddened spectra with a library of supernova spectra using the "GELATO" code (Harutyunyan et al. 2008, A.Ap. 488, 383) yields the best match for both with the spectra of type-Ia supernovae slightly before or around maximum light. For 2010bd, a match is found with a type-II supernova at a few weeks after the explosion; for 2010bc, with a type-Ia supernova at two weeks past maximum; and for 2010bg, with a type-Ia supernova around the maximum light. The spectrum of 2010bf is found to be similar to type-Ic-supernova spectra around maximum light.