GRB 170519A: BOOTES-5/JGT early optical detection

The 60 cm BOOTES-5/Javier Gorosabel Telescope at Observatorio Astronómico Nacional in San Pedro Mártir (México) 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 Astronómico Nacional in San Pedro Mártir for its excellent support. [GCN OPS NOTE(19may17), At the request of the author, the last 3 authors were added.]