Fermi GRB 240821B: Global MASTER-Net observations report

MASTER-Amur robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Blagoveshchensk State Pedagogical University) started inspect of the Fermi GRB 240821B ( Fermi GBM team, GCN 37224) errorbox 53665 sec after notice time and 65775 sec after trigger time at 2024-08-22 11:33:51 UT, with upper limit up to 16.0 mag. Observations started at twilight. The observations began at zenith distance = 32 deg. The sun altitude is -9.3 deg. The galactic latitude b = 37 deg., longitude l = 114 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2570810 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 65805 | 2024-08-22 11:33:51 | MASTER-Amur | (15h 13m 11.66s , +77d 06m 51.0s) | C | 60 | 12.7 | 65805 | 2024-08-22 11:33:51 | MASTER-Amur | (14h 42m 26.03s , +76d 38m 06.4s) | C | 60 | 15.1 | 65898 | 2024-08-22 11:35:24 | MASTER-Amur | (15h 09m 25.36s , +78d 59m 07.7s) | C | 60 | 13.0 | 65898 | 2024-08-22 11:35:24 | MASTER-Amur | (14h 33m 33.70s , +78d 30m 39.3s) | C | 60 | 15.3 | 65991 | 2024-08-22 11:36:57 | MASTER-Amur | (14h 50m 06.17s , +74d 42m 34.8s) | C | 60 | 15.7 | 65991 | 2024-08-22 11:36:57 | MASTER-Amur | (15h 17m 09.50s , +75d 11m 42.5s) | C | 60 | 13.3 | 66085 | 2024-08-22 11:38:31 | MASTER-Amur | (15h 52m 12.28s , +78d 31m 05.4s) | C | 60 | 15.7 | 66085 | 2024-08-22 11:38:31 | MASTER-Amur | (16h 28m 08.08s , +78d 59m 38.0s) | C | 60 | 13.1 | 66178 | 2024-08-22 11:40:04 | MASTER-Amur | (16h 20m 38.07s , +77d 07m 10.6s) | C | 60 | 13.1 | 66178 | 2024-08-22 11:40:04 | MASTER-Amur | (15h 49m 53.21s , +76d 38m 54.1s) | C | 60 | 15.8 | 66270 | 2024-08-22 11:41:36 | MASTER-Amur | (16h 39m 23.25s , +80d 53m 11.4s) | C | 60 | 13.5 | 66270 | 2024-08-22 11:41:36 | MASTER-Amur | (15h 56m 43.41s , +80d 24m 33.7s) | C | 60 | 15.8 | 66364 | 2024-08-22 11:43:10 | MASTER-Amur | (15h 05m 16.23s , +80d 54m 24.1s) | C | 60 | 13.4 | 66364 | 2024-08-22 11:43:10 | MASTER-Amur | (14h 22m 16.41s , +80d 25m 09.5s) | C | 60 | 16.0 | 66457 | 2024-08-22 11:44:43 | MASTER-Amur | (16h 16m 06.05s , +75d 12m 34.0s) | C | 60 | 13.5 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.