[ Previous | Next | ADS ]

Type Ia Supernova at z=0.261 Discovered in HST imaging from CLASH

ATel #3731; Teddy F. Frederiksen (Dark Cosmology Centre), Or Graur (Tel Aviv University), Jeffrey M. Silverman (UC Berkeley), Alexei V. Filippenko (UC Berkeley) and Steven A. Rodney (JHU) on behalf of the HST Higher-z SN team (PI A. Riess)
on 2 Nov 2011; 20:29 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Teddy F. Frederiksen (teddy@dark-cosmology.dk)

Subjects: Infra-Red, Optical, Supernovae, Transient

We report the discovery of a Type Ia Supernova (SN) in Hubble Space Telescope Imaging. The SN was found in subtraction images generated from observations taken on Oct 30.6 and not detected at any earlier epoch. The observations were taken with HST/WFC3 as part of CLASH: Cluster Lensing and Supernova Survey with Hubble (HST program 12065 , PI M. Postman). The position of the transient is RA = 07:17:20.115, Dec = +37:49:54.54 (J2000.0). The following magnitudes are reported: F160W = 21.51 +/- 0.15; F125W = 21.53 +/- 0.11. The SN is offset 2.3" from its likely host galaxy. The magnitude of the host is F160W = 17.23 +/- 0.04; F125W = 17.52 +/- 0.04.
Spectra of the SN and host were collected with Keck+LRIS on Nov 01.6. The host redshift is z=0.261, measured from detections of multiple emission lines. Cross-correlation of the SN spectrum with a library of SN template spectra using the SNID program (Blondin & Tonry 2007, ApJ, 666, 1024) finds the best-fit with a Type Ia SN near maximum light.