[vsnet-grb-info 25165] GRB 200227A: RATIR Optical Observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  27265
SUBJECT: GRB 200227A: RATIR Optical Observations 
DATE:    20/02/28 20:22:19 GMT
FROM:    Alan M Watson at UNAM  <alan at astro.unam.mx>

Alan M. Watson (UNAM), Nat Butler (ASU), Alexander Kutyrev (GSFC),
William H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J.
Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UVI),
Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz
(UCSC), Jesús González (UNAM), Carlos Román-Zúñiga (UNAM), Harvey
Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (U. Wash.), and Vicki
Toy (UMD) report:

We observed the field of GRB 200227A (Laha et al., GCN Circ. 27234) 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 2020/02 28.17 to 2020/02 28.24
UTC (20.84 to 22.53 hours after the BAT trigger), obtaining a total of
0.69 hours exposure in the r and i bands.

For a source within the Swift-XRT enhanced error circle (Beardmore et
al., GCN Circ. 27243), in comparison with the SDSS DR9, we obtain the
following upper limits (3-sigma):

  r	> 19.73
  i	> 20.33

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.