TITLE:   GCN CIRCULAR
NUMBER:  21424
SUBJECT: GRB 170714A: ATCA detection of the radio counterpart
DATE:    17/08/08 13:13:31 GMT
FROM:    Luigi Piro at INAF  <luigi.piro@iaps.inaf.it>

L. Piro(INAF/IAPS), R. Ricci (INAF/IRA-Bologna), M. Wieringa (ATNF,CSIRO),
E. Troja(NASA/GSFC), K. Bannister (ATNF,CSIRO) and B. Gendre (UVI, USA) 
report:

We carried out a second observation of our monitoring campaign of the 
field of the ultralong GRB 170714A (D'Ai' et al. GCN 21340; Evans et al. 
GCN 21341; Kann et al. GCN 21345; Palmer et al. GCN 21347) with ATCA on 
2017 Aug 4 for 9 hours at 17 and 21 GHz.

We detect a source at:

RA: 02h17m23.96s
Dec: +01:59'32.9"

with a 90% error of ~2.5" in DEC and ~0.1" in RA, consistent with the 
position of the GRB X-ray counterpart by Chandra (Troja et al. GCN 21396) 
and the optical source reported by de Ugarte Postigo et al. (GCN 21346).

We associate this source to the radio afterglow of the burst. The flux 
measured at 19 GHz is 71 +/- 19 uJy.

In comparison to the first ATCA observation (Ricci et al. GCN 21360), the 
present configuration improves significantly the resolution and allows us 
to distinguish the radio afterglow from the unrelated source associated to 
the NOEMA observation (de Ugarte Postigo et al., GCN 21356).

We thank the ATCA staff for scheduling this target of opportunity observation.