TITLE: GCN CIRCULAR NUMBER: 20428 SUBJECT: LIGO/Virgo G268556: VLA follow-up of iPTF17cw DATE: 17/01/11 15:39:47 GMT FROM: Alessandra Corsi at Texas Tech U. A. Corsi (TTU), M.M. Kasliwal (CalTech), S.B. Cenko (NASA/GSFC), D.A. Frail (NRAO) report on behalf of a larger collaboration: We observed the position of the broad-lined type Ic supernova iPTF17cw (Kasliwal et al. LVC GCN#20398; Kupfer et al. LVC GCN#20419)located in the error region of LIGO/ Virgo G268556 (LVC GCN#20364) with the Karl G. Jansky Very Large Array (VLA) in its A configuration. The observations started on 10 Jan 2017 02:51:16 UTC, ended on 10 Jan 2017 03:51:00 UTC, and were carried out in C-band (central frequency of about 6 GHz). A provisional reduction of our data shows a radio source located at the position of iPTF17cw. For this source, we measure a radio flux of (38.1+/-7.3) uJy at 6.2 GHz. We caution that at the present time we do not know whether this source is variable. Further observations are planned. We thank the VLA staff for rapidly executing these observations.