Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to https://gcn.nasa.gov.
New Announcement Feature, Code of Conduct, Circular Revisions. See news and announcements

GCN Circular 17947

Subject
GRB 150616A: Watcher optical upper limit
Date
2015-06-18T16:07:20Z (9 years ago)
From
Antonio Martin-Carrillo at UCD,Space Science Group <antonio.martin-carrillo@ucd.ie>
D. Murphy (UCD), A. Martin-Carrillo (UCD), M. Topinka (CTU), L. Hanlon (UCD), H. J. van Heerden (UFS), B. van Soelen (UFS) and P. J. Meintjes (UFS):

We observed the field of GRB 150616A (Lien et al., GCN Circ. #17936) using the 40cm Watcher telescope at Boyden Observatory in South Africa. 

Observations started at 22:52:09 UT, 170 seconds after the burst trigger. A series of 5 sec images were taken in the SDSS r' filter using an Andor CCD camera. 
No credible afterglow is found in any of the individual images at the enhanced XRT location (Evans et al., GCN Circ. #17937). A 3sigma upper limit for a combined 50 second exposure is given below.

Start             | End              | Exposure | Filter | Magnitude
-------------------------------------------------------------------------------------------------
22:52:09 UT | 22:53:15 UT | 10x5 sec |  r'       |  >18.9 (3sigma upper limit)

The upper limit was calculated using nearby stars from the APASS catalogue.

This message can be cited in publications.
Looking for U.S. government information and services? Visit USA.gov