[vsnet-grb-info 20615] GRB 180512A: NOT upper limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  22713
SUBJECT: GRB 180512A: NOT upper limits
DATE:    18/05/13 00:15:15 GMT
FROM:    Kasper Elm Heintz at Univ. of Iceland and DAWN/NBI  <keh14 at hi.is>

Kasper Elm Heintz (Univ. Iceland and DAWN/NBI), Daniele Malesani (DAWN/NBI and DARK/NBI), Lauri Siltala (NOT), and Pilar Montanes Rodrigues (IAC), report on behalf of a larger collaboration:

We observed the field around GRB 180512A (Deich et al., GCN 22710) with the 2.5-m Nordic Optical Telescope (NOT) equipped with ALFOSC.

Observations of 3x100 s were carried out in each of the SDSS r, i, and z filters and started at 22:48:54 UT on May 12, 47 min after trigger. We do not detect the optical counterpart within the Swift-XRT error circle and calibrated against Pan-STARRS local photometry we measure upper limits (at 3-sigma) of:

m(r) > 23.3, m(i) > 23.0, and m(z) > 22.1 AB mag.

These magnitudes are not corrected for Galactic extinction in the direction of the GRB.