GRB 200613A: Jet-break from Xinglong-2.16m optical observations
Abstract
We continued to observe the field of GRB 200613A (Fermi GBM team, GCN 27926; Bissaldi et al., GCN 27930; Ohno et al., GCN 27931) using the Xinglong-2.16m telescope equipped with the BFOSC camera. Observations were carried out starting at 12:55:02 UT on 2020-06-16, and 5x300s R-band frames were obtained. The optical afterglow (e.g., Kann et al., GCN 27935; Kennea et al., GCN 27936; Pozanenko et al., GCN 27937; Izzo et al., GCN 27939; Zhu et al., GCN 27943; Marshall, GCN 27944; Liu et al., GCN 27949; Belkin et al., GCN 27958) is still well detected in our stacked image, with R = 21.07 +/- 0.21 mag (at Tmid-T0 = 3.3175 days post-burst), calibrated with nearby Pan-STARRS1. Compared with our previous measurements, the afterglow now has turned to decay quickly, with a temporal decay index of \alpha ~ 2.5 and a break time of ~ 2.3 days post-burst. This break can be interpreted as a jet break. Further observations are planned.
- Publication:
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GRB Coordinates Network
- Pub Date:
- June 2020
- Bibcode:
- 2020GCN.27971....1F