SIMBAD references

F. Yuan, University of Michigan; R. Quimby, California Institute of Technology; J. Vinko, University of Texas; D. Chamarro, M. D. Sisson, C. Akerlof, S. B. Pandey, University of Michigan; and J. C. Wheeler and E. Chatzopoulos, University of Texas, on behalf of the ROTSE collaboration, report the discovery of a type-Ia supernova (mag about 17.5) in unfiltered CCD images taken on July 19.02 UT with the 0.45-m ROTSE-IIId telescope at the TUBITAK National Observatory at Bakirlitepe, Turkey. The new object, designated 2009ht, was also detected on the same day with the ROTSE-IIIc telescope at the H.E.S.S. site in Namibia. SN 2009ht is located at R.A. = 0:56:46.89, Decl. = -1:35:51.3 (equinox 2000.0), which is 5".1 east and 4".0 south of the center of a galaxy having z = 0.0459 in the SIMBAD database. The supernova was discovered by subtracting a reference image built from images taken in August 2008, and this field was not observed between Jan. 2009 and the discovery date. A finding chart of the transient is posted at URL http://www.rotse.net/rsvp/j005646.9-013551/j005646.9-013551.jpg. A spectrum (range 320-1000 nm) obtained on July 22.58 UT with the 10-m Keck I (+ Low Resolution Imaging Spectrometer) shows 2009ht to be a normal type-Ia supernova near maximum light. Adopting the redshift of the apparent host, the expansion velocity derived from the minimum of the Si II (rest 635.5 nm) line is about 11000 km/s.

Further to CBET 1866, D. Sand, Harvard-Smithsonian Center for Astrophysics and the Las Cumbres Observatory Global Telescope Network; M. L. Graham and C. Bildfell, University of Victoria; D. W. Just, S. Sivanandam, and S. Herbert-Fort, Steward Observatory, C. J. Pritchet, University of Victoria; H. Hoekstra, Leiden University; and D. Zaritsky, Steward Observatory, report that five supernovae were discovered with g' and r'-band images obtained at the Canada-France-Hawaii Telescope with Megacam, including an independent discovery of 2009ht. Spectroscopy was obtained with either the Hectospec instrument (July 16, 2009hu and 2009hv) or the Blue Channel Spectrograph (July 23, remaining three objects) on the MMT, as noted below. The publicly available Supernova Identification code of Blondin and Tonry (2007, Ap.J. 666, 1024) was utilized for determining spectroscopic types, indicating that 2009ht is a normal type-Ia supernova roughly a week past maximum, 2009hu is a type-Ib supernova roughly at maximum light, 2009hv is a normal type-Ia supernova around two weeks past maximum, 2009hw is a normal type-Ia supernova around two days after maximum, and 2009hx is a normal type-Ia supernova roughly one month after maximum. The objects' discovery magnitudes and spectroscopic redshift (z) are tabulated below:

---------------------------------------------------------------------------— SN 2009 UT R.A. (2000.0) Decl. g' r' z ---------------------------------------------------------------------------— 2009ht July 19 0 56 46.92 - 1 35 51.3 17.5 17.5 0.044 2009hu June 25 14 53 29.82 +18 35 31.1 22.6 21.9 0.13 2009hv June 25 14 54 32.92 +18 39 42.0 18.6 18.6 0.054 2009hw July 17 19 20 34.05 +43 33 45.6 19.1 18.6 0.06 2009hx July 17 22 49 12.74 +11 20 14.4 22.6 21.4 0.14 ---------------------------------------------------------------------------—

SN 2009ht is located 5".25 east and 3".83 south of its host galaxy (which itself has magnitudes g' = 16.0 and r' = 15.2). SN 2009hu had magnitudes g' = 22.0 and r' = 21.2 on July 17; it is located 0".97 west and 2".87 south of its host galaxy (which itself has magnitudes g' = 19.2, r' = 18.6). SN 2009hv had magnitudes g' = 19.6, r' = 18.9 on July 17; it is located 0".26 east and 2".49 north of its host galaxy (which itself has magnitudes g' = 23.8, r' = 23.4). SN 2009hw is located 0".88 east and 1".93 south of the center of its host galaxy (which itself has magnitudes g' = 17.4, r' = 16.8). SN 2009hx has not apparent host galaxy to limiting magnitudes around g = r = 24; further imaging after the supernova has faded will further constrain the brightness of any possible host.