TITLE:   GCN CIRCULAR
NUMBER:  21117
SUBJECT: GRB 170519A: BOOTES-5/JGT early optical detection
DATE:    17/05/19 22:58:31 GMT
FROM:    Alberto Castro-Tirado at Inst.de Astro. de Andalucia  <ajct@iaa.es>

A. J. Castro-Tirado (IAA-CSIC & ISA-UMA), J. C. Tello, R. Cunniffe, 
B.-B. Zhang, Y. Hu and A. Gonzalez-Rodriguez (IAA-CSIC), A. Castellon 
(Univ. de Malaga), D. Hiriart, W. H. Lee (UNAM), S. Jeong and I. H. Park (SKKU)
and P. Kubanek (Inst. of Physics, CZ) on behalf of a larger collaboration, report:

The 60 cm BOOTES-5/Javier Gorosabel Telescope at Observatorio 
Astron��mico Nacional in San Pedro M��rtir (M��xico) automatically 
responded to the Swift trigger of GRB 170519A (Ukwatta et al., GCN 
21106). The first unfiltered images (60 s exposures) were obtained at 
05:15:08.9 UT (5 min after the burst). At the position of the Swift 
X-ray afterglow, we confirm the optical afterglow detected by UVOT, at a 
magnitude of 16.6+/-0.1 when compared to the GSC2.3 catalog, and fading 
during the late-time BOOTES-5/JGT observation.

We thank the staff at Observatorio Astron��mico Nacional in San Pedro 
M��rtir for its excellent support.

[GCN OPS NOTE(19may17),  At the request of the author, the last 3 authors
were added.]