2009CBET.1681....1D

Further to CBET 1676, A. J. Drake, S. G. Djorgovski, R. Williams, A. Mahabal, and M. J. Graham, California Institute of Technology; M. Catelan, Pontificia Universidad Catolica; and E. C. Beshore and S. M. Larson, Lunar and Planetary Laboratory, University of Arizona, report the CRTS discovery of two apparent supernovae in unfiltered CSS images: ------------------------------------------------------------------------— SN 2008 UT R.A. (2000.0) Decl. Mag. Offset ------------------------------------------------------------------------— 2008iu Oct. 30.36 4 36 55.20 - 0 21 35.6 18.1 0".4 E, 0".7 S 2008iv Dec. 22.50 9 39 49.91 + 7 03 47.8 18.7 16".0 E, 9".3 S ------------------------------------------------------------------------— The Palomar 1.52-m reflector (+ Gunn filters) was used for follow-up photometry with Gunn g, r, and i filters, as listed below (otherwise, magnitudes unfiltered CSS images, where stated).

The host galaxy of 2008iu, SDSS J043655.17-002136.3, has Gunn magnitudes u = 22.5, g = 22.6, r = 22.1, i = 21.8, and z = 22.1. Additional magnitudes for 2008iu: 2008 Mar. 8.11 UT, [20.4 (CSS); Oct. 6.49, 18.1 (CSS); Oct. 9.48, 18.1 (CSS); Oct. 31.49, g = 18.1, r = 18.2, i = 18.0; Nov. 19.39, 18.3 (CSS); Dec. 3.36, 18.3 (CSS); Dec. 29.27, 18.6 (CSS); 2009 Jan. 20.24, 18.8 (CSS). A noisy spectrum (range 380-520 nm) of 2008iu was obtained on Dec. 4.15 with the SMARTs 1.5m telescope. Cross-correlation with a library of supernova spectra using the "Supernova Identification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) indicates that 2008iu is most similar to the type-Ic supernova 1998bw at 34 days after maximum light; this is consistent with the peak time derived from the light curve.

The host galaxy of 2008iv, SDSS J093948.83+070357.1, has Gunn magnitudes u = 18.7, g = 17.8, r = 17.4, i = 17.2, and z = 17.1, and redshift z = 0.019. Additional magnitudes for 2008iv: 2008 Dec. 7.45, [20.0 (CSS); 2009 Jan. 17.53, 18.6 (CSS).