[AAVSO-HEN] GRB 070621: Watcher Observations

[grb at aavso.org]

The following is a GCN Circular circulated via the AAVSO network.
For an archive and more information on circulars visit:
http://lheawww.gsfc.nasa.gov/docs/gamcosray/legr/bacodine/gcn3_archive.html

TITLE:   GCN CIRCULAR
NUMBER:  6562
SUBJECT: GRB 070621: Watcher Observations
DATE:    07/06/22 01:28:07 GMT
FROM:    John French at UCD,Ireland  <jfrench at bermuda.ucd.ie>

John French (University College Dublin), Petr Kubanek (GACE Valencia),
Gary Melady (University College Dublin), Martin Jelinek (IAA CSIC Granada)

report on behalf of the Watcher collaboration:

The Watcher 40cm robotic telescope, located at Boyden Observatory,
South Africa, began imaging the field of GRB 070621
(Sbarufatti et al., GCN 6560) at 23:18:21 UT, 40s after the Swift trigger.

Our first 10s unfiltered image shows no new source in the XRT error circle
down to an R-band limiting magnitude of 16.1. Subsequent 10s exposures
were combined to create a 360s exposure with a mean time of 23:21:47
(247s after the trigger). No new source is detected in the XRT error
circle down to an R-band limiting magnitude of 17.9.
Observations are ongoing.