Support ATel At Patreon

[ Previous | Next | ADS ]

Discovery of Two Possible Supernovae in Rich Galaxy Clusters from SIRCLS

ATel #5390; M. L. Graham (UCB), D. J. Sand (Texas Tech), C. J. Pritchet (U. of Victoria), J. Richard (CRAL), D. Zaritsky (U. of Arizona), H. Hoekstra (Leiden U.), C. J. Bildfell (U. of Victoria), M. Gladders (U. of Chicago), H. Ebeling (IfA), J. P. Kneib (OAMP), J. Kezwer (U. of Victoria), S. Fabbro (U. of Victoria), R. Gavazzi (IAP), M. Limousin (OAMP), E. Jullo (OAMP), and J. Parrent (LCOGT, Dartmouth)
on 12 Sep 2013; 17:40 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Melissa Lynn Graham (mgraham@lcogt.net)

Subjects: Optical, Supernovae

We report the discovery of two possible supernovae within a projected distance of <1 Mpc of rich galaxy clusters by the Survey at Intermediate Redshift for Cluster and Lensed Supernovae (SIRCLS).

1. We detect a new source at RA=16:21:30.42 Dec=+38:08:56.5 on UT 2013 Sept 1.3 with an r-band magnitude of 22.6. This PSN was detected in images obtained with MegaCam at the Canada-France-Hawaii Telescope, and is not detected in a previous image taken on UT 2013-08-01 (or any previous monthly images back to 2013-04-03). The PSN is near the core of an apparent red sequence galaxy with a projected clustercentric offset of 0.6 Mpc from galaxy cluster MACSJ1621.3+3810 (RA=16:21:00 Dec=+38:10:00 z=0.465). The galaxy is in SDSS with a magnitude of r=20.33 and (g-r)=1.55, consistent with red sequence membership. If associated with the galaxy cluster, the intrinsic magnitude of this transient is approximately -19.5 magnitudes, which is brighter than the average but consistent with a Type Ia SN at peak brightness. Given its low host offset, it could be nuclear activity.

2. We detect a new source at RA=22:44:57.71 Dec=+26:39:31.1 on UT 2013 Aug 31.4 with an r-band magnitude of 23.1. This PSN was detected in images obtained with MegaCam at the Canada-France-Hawaii Telescope, and is not visible in a previous image taken on UT 2013-08-02. This PSN is has a projected clustercentric offset of 0.6 Mpc from the galaxy cluster MACSJ2245.0+2637 (RA=22:45:04.6 Dec=+26:38:05 z=0.3). It is offset 0.7"E 2.4"S from an SDSS galaxy with r=19.60 and (g-r)=0.97, and offset 0.5"E 0.5"S from a very faint SDSS galaxy of r>22. Although the fainter galaxy is closer, the PSN is within 4 effective radii of the brighter potential host. The colors of both galaxies are bluer than the red sequence, but may still be cluster members. If associated with the galaxy cluster, the intrinsic magnitude of this transient is currently approximately -18.