TITLE:   GCN CIRCULAR
NUMBER:  27760
SUBJECT: GRB 200519A: BOOTES-3/YA optical counterpart observations
DATE:    20/05/19 21:41:56 GMT
FROM:    Youdong HU at IAA-CSIC  <youdong@iaa.es>

Y.-D. Hu, E. Fernandez-Garcia, A. J. Castro-Tirado (IAA-CSIC), I. 
Carrasco and C. Perez del Pulgar (Univ. de Malaga), M. D. 
Caballero-Garcia (ASU-CAS, CZ) and R. Querel (NIWA), on behalf of a 
larger collaboration, report:

The 60cm BOOTES-3/YA robotic telescope at NIWA Lauder in Otago (New 
Zealand) automatically responded to the Swift trigger of GRB 200519A 
(Sbarufatti et al. GCNC 27756). The first image (clear filter) were 
obatined starting at 11:20:57 UT (~ 34 s after trigger). At the position 
reported by Swift/UVOT (Sbarufatti et al. GCNC 27756), we found the 
optical counterpart with a magnitude of 14.96+-0.12 mag in the 1s 
exposure image whose median time at 52s that also reported by iTelescope 
(Kong et al. GCNC 27757) and LCO (Strausbaugh et al. GCNC 27759), which 
calibrated with nearby stars in USNO-B 1.0 catalog. Further analysis is 
ongoing.

We thank the staff at NIWA for its excellent support.