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

GCN Circular 18123

GRB 150811A: LCOGT-McDonald afterglow detection
2015-08-11T08:48:37Z (9 years ago)
Jure Japelj at U. of Ljubljana,Slovenia <>
J. Japelj (U. Ljubljana), C. Guidorzi (U. Ferrara), S. Kobayashi (LJMU)
on behalf of a large collaboration report:

We observed the position of GRB 150811A (Evans et al. GCN Circ.
18119) with the 1-m McDonald telescope (Fort Davis, US), a
member of the Las Cumbres Observatory network. Observations
started on August 11 at 06:13:35 UT, i.e., 127 minutes after
the GRB trigger time and were done with the r' and i' filters.

We detect the optical afterglow (Butler et al. GCN 18120, Zheng
et al. GCN 18121, Kuin et al. 18122) with the magnitude of
r' = 18.4 +- 0.2 at 132 min after the GRB trigger. Magnitude has
been calibrated against nearby USNOB-1 stars.
Looking for U.S. government information and services? Visit