GRB 211024B: CAHA 2.2m Detection; ultra-long GRB?
Abstract
We observed the optical afterglow of the very long Swift GRB 211024B (Gropp et al., GCN #30980; Zhu et al., GCN #30984) with CAFOS mounted on the 2.2m Telescope at Calar Alto, Almeria, Spain. We obtained 30 x 90 s in the SDSS i' band under mediocre conditions. At the position of the GRB afterglow discovered by Nanshan/NEXT (Zhu et al., GCN #30984), we detect a source. Against one Pan-STARRS comparison star, we measure: i' = 20.27 +- 0.05 mag (AB) at 0.2485 d after the GRB. We note the XRT light curve at time of writing (https://www.swift.ac.uk/xrt_curves/01081073/ Evans et al., GCN #30994) shows a certain resemblance to that of the ultra-long GRB 111209A, being relatively flat until 10 ks before dropping off very steeply. The lack of early data prevents further conclusions for now. Further follow-up is warranted.
- Publication:
-
GRB Coordinates Network
- Pub Date:
- October 2021
- Bibcode:
- 2021GCN.30995....1K