TITLE:   GCN CIRCULAR
NUMBER:  29921
SUBJECT: GRB 210430A: BOOTES-1 optical limit
DATE:    21/05/01 18:10:01 GMT
FROM:    Youdong HU at IAA-CSIC  <huyoudong072@hotmail.com>

T.-R Sun, Y.-D. Hu, E. Fernandez-Garcia, A. J. Castro-Tirado, M.D. Caballero-Garcia, M. A. Castro Tirado, F. Rendon (IAA-CSIC), C. Perez del Pulgar, A. Castellon and A. J. Reina (Univ. de Malaga)  on behalf of a larger collaboration, report:

Following the detection of GRB 210430A by Swift (Moss et al. GCNC 29918), we triggered the 0.3m BOOTES-1B robotic telescope at the BOOTES-1 astronomical station at ESAt/INTA-CEDEA in Mazag¨Žn (Huelva, Spain), gathering images starting on Apr 30, 20:30 UT, about 9.8 hours after the onset of the GRB. After co-adding the corresponding images, nothing is found within the GRB 210430A error box down to 18.4 limiting magnitude, after calibrating the image with G mag in the GAIA DR2 catalogue.

We thank the staff at INTA-CEDEA for their excellent support.