[vsnet-grb-info 20686] GRB 180614A: NOT optical upper limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  22784
SUBJECT: GRB 180614A: NOT optical upper limits 
DATE:    18/06/15 12:42:31 GMT
FROM:    Kasper Elm Heintz at Univ. of Iceland and DAWN/NBI  <keh14 at hi.is>

Kasper E. Heintz (Univ. of Iceland and DAWN/NBI), Johan P. U. Fynbo (DAWN/NBI), Daniele B. Malesani (DAWN/NBI and DARK/NBI), Jyri J. Lehtinen (MPS), Teemu Willamo (Univ. of Helsinki), and Paco Galindo (NOT), report on behalf of a larger collaboration:

We observed the field around GRB 180614A (Gropp et al., GCN 22780) with the 2.5-m Nordic Optical Telescope (NOT) equipped with StanCam.

Observations of 3x100 s were carried out in the R filter and started at 04:12:59 UT on June 15, 8.93 hr after trigger. We do not detect the optical counterpart within the enhanced Swift-XRT error circle and calibrated against local photometry from the USNO-B1 catalog we measure an upper limit (at 3-sigma) of m(R) > 22.9 AB mag.

This upper limit is not corrected for the Galactic extinction of A_V = 0.36 mag (Schlafly & Finkbeiner, 2011, ApJ, 737, 103) in the direction of the GRB.