CRTS discovery of a long timescale type-IIn SN
ATel #2149; A. J. Drake, S. G. Djorgovski, D. Levitan, A. A. Mahabal, M. J. Graham, R. Williams (Caltech); A. Myers (UIUC); M. Catelan (PUC); E. C. Beshore, S. M. Larson (LPL/UA); E. Christensen (Gemini Observatory)
on 6 Aug 2009; 07:52 UT
Credential Certification: Andrew J. Drake (ajd@cacr.caltech.edu)
Subjects: Optical, Supernovae, Transient
We report on the discovery of an energetic type-IIn SN by the Catalina Real-Time Transient Survey (CRTS).
The CSS and Palomar 60" light curves show that the SN's brightness rose from V-mag~20.2 to 18.5 by Dec 30th 2008, and then very slowly decline to mag ~19.3 by July 31st 2009. A spectrum was taken with the Palomar 5m+DBSP on 2009 July 23 UT and shows strong, broad, asymmetric H-alpha emission along with H-beta, H-gamma, and Helium lines at redshift z=0.069. The spectrum most resembles the type-IIn SN 2007rt at 260 days past explosion (Trundle et al. 2009).
A faint host galaxy is seen in SDSS data (mags: u=23.2, g=22.0, r=21.4, i=20.9, z=20.6). The peak absolute magnitude of the SN, derived from the redshift, is Mv= -18.8 (typical for a type-IIn). Such slow evolution suggests significant ongoing interaction with CSM similar to the very long timescale type-IIn 2008iy (ATEL#2010).
Current CRTS candidate and confirmed SNe can be found at here.
More details of the CRTS project are available at http://crts.caltech.edu.
