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GCN Circular 23089

GRB 180805B: COATLI Optical Observations
2018-08-06T17:18:16Z (6 years ago)
Alan M. Watson at Instituto de Astronomia UNAM <>
Alan M. Watson (UNAM), Nat Butler (ASU), Rosa L. Becerra (UNAM), William
H. Lee (UNAM), Carlos Rom��n-Z����iga (UNAM), Alexander Kutyrev (GSFC), and
Eleonora Troja (GSFC) report:

We observed the field of the short GRB 180805B (D'Avanzo et al., GCN
Circ. 23076) with the COATLI 50-cm telescope and interim imager at the
Observatorio Astron��mico Nacional on the Sierra de San Pedro M��rtir
( from 2018-08-06 08:01 to 11:48 UTC
(18.98 to 22.77 hours after the trigger), obtaining a total of 2.98
hours of exposure in the w filter.

We do not detect any optical sources within the enhanced XRT error
region (Evans et al., GCN Circ. 23077) to a 5-sigma limiting magnitude

w > 22.5

This magnitude is calibrated against the USNO-B1 catalog (adjusted to an
approximate AB system) and is not corrected for Galactic extinction in
the direction of the GRB.

We thank the COATLI technical team (Fernando ��ngeles, Oscar Chapa,
Salvador Cuevas, Alejandro Farah, Jorge Fuentes, Rosal��a Langarica,
Fernando Quir��s, and Carlos Tejada) and the staff of the Observatorio
Astron��mico Nacional.
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