2009CBET.1936....1C

Further to CBET 1932, M. Catelan, A. J. Drake, S. G. Djorgovski, A. Mahabal, M. J. Graham, R. Williams, E. C. Beshore, S. M. Larson, and E. Christensen report the CRTS discovery of another supernova in unfiltered Catalina Sky Survey (CSS) images:

---------------------------------------------------------------------------— SN 2008 UT R.A. (2000.0) Decl. Mag. Offset ---------------------------------------------------------------------------— 2008ja July 1.43 23 44 12.82 + 7 52 23.6 20.1 < 1" ---------------------------------------------------------------------------—

Further CSS magnitudes for 2008ja: 2008 Jan. 10.38 UT, [20.3; Dec. 30.13, 18.5; 2009 Aug. 17.38, 19.5. The full CSS lightcurve shows a slow rise over approximately six months, followed by a continuing decline over the past eight months. A faint host galaxy is seen in Sloan Digital Sky Survey data (magnitudes u = 23.2, g = 22.0, r = 21.4, i = 20.9, z = 20.6). A spectrogram (range 350-900 nm), obtained with the Palomar 5-m reflector (+ DSBS) on 2009 July 22.43, shows the object to be a type-IIn supernova with strong, broad, asymmetric H-alpha emission, along with H-beta, H-gamma, and helium lines at redshift z = 0.069. The spectrum most resembles that of supernova 2007rt at 260 days past explosion (Trundle et al. 2009, http://lanl.arxiv.org/abs/0904.0119).

SN 2009is (cf. CBET 1932) is located less than an arcsecond from its apparent faint host galaxy, which has USNO-B red mag 18.5-19.