[vsnet-grb-info 16613] GRB 150530A: RATIR Optical Observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  17894
SUBJECT: GRB 150530A: RATIR Optical Observations
DATE:    15/05/31 19:31:54 GMT
FROM:    Alan M. Watson at Instituto de Astronomia UNAM  <alan at astro.unam.mx>

Alan M. Watson (UNAM), Nat Butler (ASU), Alexander Kutyrev (GSFC),
William H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB),
Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino
Cucchiara (ORAU/GSFC), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico
Ramirez-Ruiz (UCSC), José A. de Diego (UNAM), Leonid Georgiev (UNAM),
Jesús González (UNAM), Carlos Román-Zúñiga (UNAM), Neil Gehrels (GSFC),
and Harvey Moseley (GSFC) report:

We observed the field of GRB 150530A (Starling et al., GCN 17888) with the
Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the
1.5m Harold Johnson Telescope at the Observatorio Astronómico Nacional on
Sierra San Pedro Mártir from 2015/05 31.32 to 2015/05 31.45 UTC (20.08
to 23.21 hours after the BAT trigger), obtaining a total of 2.49 hours
exposure in the r, i, and z bands.

For a source within the Swift-XRT error circle, in comparison with 2MASS, we
obtain the following upper limits (3-sigma):

  r > 24.42
  i > 24.18
  z > 20.44

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

We thank the staff of the Observatorio Astronómico Nacional in San Pedro
Mártir.