[vsnet-grb-info 16273] GRB 150309A: BOOTES-1 and -2 upper limit

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  17554
SUBJECT: GRB 150309A: BOOTES-1 and -2 upper limit
DATE:    15/03/10 00:13:17 GMT
FROM:    Alberto Castro-Tirado at Inst.de Astro. de Andalucia  <ajct at iaa.es>

R. Cunniffe, M. Jelinek, Y. Hu, S. Jeong, S. R. Oates and B. Zhang
(IAA-CSIC) and A. J. Castro-Tirado (IAA-CSIC and ISA-UMA), on behalf of a
larger collaboration, report:

Both the 60 cm BOOTES-2/TELMA and the 30 cm BOOTES-1 robotic telescopes in
South Spain automatically responded to the Swift trigger of GRB 150309A
(Cummings et al., GCN 17553). The first exposure started at 23:04:33 UT
(86s after the trigger) and a sequence of 20 images was obtained (3s each,
clear filter). A median combined image revealed no optical counterpart at
the enhanced XRT error circle down to 18 mag. Further observations are
ongoing.