GRB 220521A: MITSuME Akeno optical upper limits
Abstract
We observed the field of GRB 220521A (The Fermi GBM team GCN Circular #32075, Dichiara et al. GCN Circular #32076, Evans et al. GCN Circular #32077, Malesani and Pursimo et al. GCN Circular #32078, Fynboet al. GCN Circular #32079, Evans et al. GCN Circular #32081, Goranskij et al. GCN Circular #32082, Kuin and Dichiara GCN Circular #32085, Tohuvavohu et al. GCN Circular #32086, Watson et al. GCN Circular #32087, Nazarov et al. GCN Circular #32088, Poolakkil and Meegan GCN Circular #32089, Lien et al. GCN Circular #32090, Strausbaugh et al. GCN Circular #32091) with the optical three color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50 cm telescope Akeno. The observation with a series of 60 sec exposures started at 2022-05-22 11:56:05 UT (12.6 hours after the Fermi/GBM trigger). We stacked the images with good conditions. We did not detect the optical afterglow (Malesani et al. GCN Circular #32078, Goranskij et al. GCN Circular #32082, Strausbaugh et al. GCN Circular #32091, Rastinejad et al. GCN Circular #32097, Cucchiara et al. GCN Circular #32099). We obtained the 5-sigma limits of the stacked images as follows. T0+[hour] | MID-UT | T-EXP[sec] | 5-sigma limits ------------------------------------------------------------------------------------------------ 16.6 | 2022-05-22 15:56:34 | 6780 | g' > 19.3, Rc > 19.1, Ic > 18.6 ------------------------------------------------------------------------------------------------ T0+ : Elapsed time after the burst T-EXP: Total Exposure time We used PS1 catalog for flux calibration. The magnitudes are expressed in the AB system. The images were processed in real-time through the MITSuME GPU reduction pipeline (Niwano et al. 2021, PASJ, Vol.73, Issue 1, Pages 4-24; https://github.com/MNiwano/Eclaire).
- Publication:
-
GRB Coordinates Network
- Pub Date:
- May 2022
- Bibcode:
- 2022GCN.32101....1S