Swift GRB220521.97: Global MASTER-Net observations report

MASTER-Tavrida robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Lomonosov MSU, SAI Crimea astronomical station) was pointed to the Swift GRB220521.97 (trigger No 1107466,18h 20m 47.28s , +10d 23m 02.4s, R=0.05) errorbox 13 sec after notice time and 33 sec after trigger time at 2022-05-21 23:20:54 UT, with upper limit up to 15.9 mag. The observations began at zenith distance = 35 deg. The sun altitude is -21.6 deg. MASTER-Kislovodsk robotic telescope located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) was pointed to the Swift GRB220521.97 errorbox 16 sec after notice time and 36 sec after trigger time at 2022-05-21 23:20:57 UT, with upper limit up to 17.4 mag. The observations began at zenith distance = 33 deg. The sun altitude is -19.7 deg. The galactic latitude b = 11 deg., longitude l = 39 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1980468 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 39 | MASTER-Tavrida | P\ | 10 | 15.4 | 41 | MASTER-Kislovodsk | P| | 10 | 16.4 | 61 | MASTER-Kislovodsk | P| | 50 | 17.4 | Coadd 59 | MASTER-Kislovodsk | P| | 10 | 16.3 | 68 | MASTER-Tavrida | P\ | 10 | 15.5 | 77 | MASTER-Kislovodsk | P| | 10 | 16.2 | 100 | MASTER-Kislovodsk | P| | 20 | 17.1 | 103 | MASTER-Tavrida | P\ | 20 | 15.9 | 128 | MASTER-Kislovodsk | P| | 20 | 17.2 | 142 | MASTER-Tavrida | P\ | 20 | 15.9 | 161 | MASTER-Kislovodsk | P| | 30 | 17.2 | 204 | MASTER-Kislovodsk | P| | 40 | 17.4 | 257 | MASTER-Kislovodsk | P| | 50 | 17.2 | The observation and reduction will continue. The message may be cited.