TITLE:   GCN CIRCULAR
NUMBER:  31901
SUBJECT: GRB 220412A: BOOTES-network optical upper limits
DATE:    22/04/14 00:05:31 GMT
FROM:    Youdong HU at IAA-CSIC  <huyoudong072@hotmail.com>

Y.-D. Hu, E. Fernandez-Garcia, A. J. Castro-Tirado, T.-R. Sun, M. D. Caballero-Garcia, R. Sanchez-Ramirez (IAA-CSIC),  D. Hiriart and W. H. Lee (UNAM), C. Perez del Pulgar,  A. Castellon, I. Carrasco, A. Reina (Univ. de Malaga), I. H. Park (SKKU) and F. Rendon (IAA-CSIC and INTA-CEDEA) on behalf of a larger collaboration, report:

Following the detection of GRB 220412A by Swift (Klingler et al., GCNC 31881), the 0.3m BOOTES-1B robotic telescope in Mazagon (Huelva), southern Spain, automatically responded to this burst on Apr 12 at 22:41 UT (i.e. ~16.1 hours after trigger). In the co-added frame (52 x 60 s, clear filter), no source is detected within the enhanced XRT position (Evans et al., GCNC 31887) down to 19.2 mag.

Later on, the 60cm BOOTES-5/JGT robotic telescope at Observatorio Astronomico Nacional in San Pedro Martir (Mexico) automatically responded to this burst on Apr 13 at 03:33 UT (i.e. ~ 21 hrs after trigger). In the co-added image (45 x 60 s, clear filter), no optical afterglow is detected within the enhanced XRT position (Evans et al., GCNC 31887) down to 20.3 mag.

Although the candidate reported by RATIR (Watson et al. GCNC 31882, GCNC 31898) is not detected, those non-detections are consistent with the reports from Swift/UVOT (Klingler et al., GCNC 31881, Breeveld et al. GCNC 31885), MITSuME (Murata et al. GCNC 31891) and MASTER-Net (Lipunov et al., GCNC 31880).

We thank the staff at INTA-CEDEA and San Pedro Martir Observatory for their excellent support.