{
  "circularId": 6618,
  "eventId": "SN 2007bg",
  "bibcode": "2007GCN..6618....1P",
  "body": "J. L. Prieto, K. Z. Stanek & J. F. Beacom (Ohio State) report:\n\nIn a study of supernova hosts (Prieto, Stanek & Beacom 2007,\narXiv:0707.0690v1 [astro-ph]), the recent broad-lined SN Ic 2007bg at\nz=0.034 (Quimby et al. 2007, CBET 927; IAUC 8834;  Harutyunyan et al.\n2007, CBET 948), was identified as a good candidate for an off-axis GRB.\n\nThe supernova, discovered on April 16 2007 (CBET 927, IAUC 8834), is\nlocated at 1.6 arcsec North and 4.0 arcsec East of a source identified in\nthe SDSS-DR6 catalog, SDSS J114925.74+514920.2, which has model magnitudes\ng=21.82 +/- 0.07, r=21.12 +/- 0.07 (uncorrected for Galactic extinction;\nAg=0.08, Ar=0.06) and estimated photometric redshift between 0.3 and 0.4.\nThere is a fainter source at ~2\" from the position of the supernova\nclearly detected in the SDSS g-band image, and which is not identified in\nthe SDSS-DR6 catalog.  This fainter source is most likely the host galaxy\nof SN 2007bg (CBET 948). A 1x1 arcmin SDSS g-band image around the\nposition of the supernova can be found here:\n\nhttp://www.astronomy.ohio-state.edu/~prieto/sn07bg_host.gif\n\nWe used Sextractor to measure a difference of 1.7 mag in g-band between\nthe likely host and SDSS J114925.74+514920.2. At the redshift of the\nsupernova, z=0.034 (CBET 927), this makes the likely host an extremely\nlow-luminosity galaxy with M_B ~ -12, one of the least-luminous supernova\nhosts ever observed. Such a low-luminosity host is certain to be very\nmetal poor (~1/20 solar; Lee et al. 2006, ApJ, 647, 970L), and therefore\nthis supernova is a very good candidate for association with an off-axis\nGRB (e.g., Stanek et al. 2006, AcA, 56, 333). We encourage follow-up\nobservations to look for an off-axis GRB jet.\n\nThis message may be cited.",
  "editedOn": 1777053101418,
  "version": 2,
  "createdOn": 1184186427000,
  "subject": "SN 2007bg - off-axis GRB?",
  "submitter": "Krzysztof Z. Stanek at CfA  <kstanek@cfa.harvard.edu>",
  "editedBy": "Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov>",
  "email": "kstanek@cfa.harvard.edu"
}