TITLE: GCN CIRCULAR NUMBER: 21815 SUBJECT: LIGO/VIRGO G298048: Radio detection of SSS17a at 6 GHz with the VLA DATE: 17/09/04 22:14:59 GMT FROM: Alessandra Corsi at Texas Tech U. A. Corsi (TTU), G. Hallinan (Caltech), K. Mooley (Hintze Fellow, Oxford), D.A. Frail (NRAO), M.M. Kasliwal (Caltech), N.T. Palliyaguru (TTU) report on behalf of a larger GROWTH collaboration: We observed the field of SSS17a/DLT17ck (e.g., Coulter et al. LVC GCN 21529; Allam et al. LVC GCN 21530; Yang et al. LVC GCN 21531), the possible counterpart of G298048 (LVC, LVC GCN 21505) in NGC 4993, with the Karl G. Jansky VLA in its B configuration (program 16A-206; PI: Corsi). The observation lasted about 1.25 hr, starting on 17-Sep-03 23:30:57 UT, and was conducted in C-band (approximate central frequency of 6 GHz). We report the detection of a radio source with S/N of about 5. This source was not seen in previous epochs down to similar limits (e.g. Corsi et al., LVC GCN 21664). The radio position is within the astrometric errors of the optical position of SSS17a. We have confirmed this source through comparison with contemporaneous S-band observations reported by Mooley et al. (see companion LVC GCN by Mooley et al.). Further observations are planned immediately. We thank the VLA staff for scheduling these observations.