TITLE:   GCN CIRCULAR
NUMBER:  21900
SUBJECT: LIGO/Virgo G298048: ATCA monitoring of SSS17a in NGC 4993
DATE:    17/09/21 06:42:36 GMT
FROM:    Eleonora Troja at GSFC/Swift  <nora.gsfc@gmail.com>

R. Ricci (INAF), M. Wieringa (CSIRO), L. Piro (INAF)
and E. Troja (UMD/GSFC) report:

On 15 Sep 2017, 3rd epoch of our monitoring campaign, we observed
the field of SSS17a (Coulter et al.,LVC GCN 21529) with the Australia
Telescope Compact Array (ATCA) at the central frequencies of 16.7 and
21.2 GHz, each with a bandwidth of 2 GHz.

At the position of the optical/IR source (Adams et al., LVC GCN 21816)
we report the following 3-sigma upper limit:

17/21 GHz flux density < 42 uJy

We thank the CSIRO staff for approving and executing the observations.