GRB 210402A: DDOTI Upper Limits
Abstract
We observed the field of the Swift/BAT GRB 210402A (Page et al., GCN Circ. 29743) with the DDOTI wide-field imager at the Observatorio Astronómico Nacional on Sierra San Pedro Martir (http://ddoti.astroscu.unam.mx) from 2021-04-03 02:52 UTC to 2021-04-03 12:18 UTC (from 4.8 to 14.2 hours after the trigger). We observed a region covering aproximately 7 degrees in RA and 10 degrees in declination (about 70 square degrees), including the XRT position in the w filter, and obtained 23ks of exposure. We calibrated our images against the APASS catalog. Compared to the USNO-B1, Pan-STARRS DR1, and APASS DR10 catalogs, we do not detect a source at the X-ray position to a 3-sigma limiting magnitude of w = 23.2. Our non-detection is consistent with the non-detections reported by Zhu et al. (GCN Circ. 29745) and Leonini et al. (GCN Circ. 29747). We thank the staff of the Observatorio Astronomico Nacional in San Pedro Martir.
- Publication:
-
GRB Coordinates Network
- Pub Date:
- April 2021
- Bibcode:
- 2021GCN.29752....1B