Swift GRB 210730A: 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 GRB 210730A ( E. Sonbas et al., GCN 30548) errorbox 47961 sec after notice time and 47903 sec after trigger time at 2021-07-30 18:17:14 UT, with upper limit up to 19.2 mag. Observations started at twilight. The observations began at zenith distance = 54 deg. The sun altitude is -11.0 deg. MASTER-IAC robotic telescope located in Spain (IAC Teide Observatory) was pointed to the Swift GRB 210730A errorbox 64883 sec after notice time and 64826 sec after trigger time at 2021-07-30 22:59:17 UT, with upper limit up to 17.7 mag. The observations began at zenith distance = 76 deg. The sun altitude is -34.0 deg. MASTER-Kislovodsk robotic telescope located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) was pointed to the Swift GRB 210730A errorbox 71489 sec after notice time and 71432 sec after trigger time at 2021-07-31 00:49:22 UT, with upper limit up to 16.5 mag. Observations started at twilight. The observations began at zenith distance = 65 deg. The sun altitude is -11.7 deg. The galactic latitude b = 41 deg., longitude l = 141 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1675497 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 47934 | MASTER-Tavrida | C | 60 | 17.0 | 48488 | MASTER-Tavrida | C | 60 | 17.9 | 48962 | MASTER-Tavrida | C | 60 | 18.4 | 49437 | MASTER-Tavrida | C | 60 | 18.8 | 49912 | MASTER-Tavrida | C | 60 | 18.7 | 50386 | MASTER-Tavrida | C | 60 | 19.1 | 50684 | MASTER-Tavrida | C | 180 | 18.9 | 51671 | MASTER-Tavrida | C | 180 | 19.2 | 64916 | MASTER-IAC | C | 180 | 17.5 | 64916 | MASTER-IAC | C | 180 | 17.3 | 65096 | MASTER-IAC | C | 540 | 17.7 | Coadd 65131 | MASTER-IAC | C | 180 | 17.2 | 65131 | MASTER-IAC | C | 180 | 16.8 | 65311 | MASTER-IAC | C | 540 | 17.5 | Coadd 65341 | MASTER-IAC | C | 180 | 17.2 | 65341 | MASTER-IAC | C | 180 | 17.0 | 65551 | MASTER-IAC | C | 180 | 17.1 | 65551 | MASTER-IAC | C | 180 | 16.8 | 65760 | MASTER-IAC | C | 180 | 17.0 | 65760 | MASTER-IAC | C | 180 | 17.0 | 65970 | MASTER-IAC | C | 180 | 17.2 | 65970 | MASTER-IAC | C | 180 | 16.7 | 66179 | MASTER-IAC | C | 180 | 17.0 | 66179 | MASTER-IAC | C | 180 | 16.9 | 66394 | MASTER-IAC | C | 180 | 17.1 | 66394 | MASTER-IAC | C | 180 | 16.8 | 66604 | MASTER-IAC | C | 180 | 17.0 | 66604 | MASTER-IAC | C | 180 | 16.8 | 66815 | MASTER-IAC | C | 180 | 17.1 | 66815 | MASTER-IAC | C | 180 | 16.6 | 67023 | MASTER-IAC | C | 180 | 17.0 | 67023 | MASTER-IAC | C | 180 | 16.7 | 67238 | MASTER-IAC | C | 180 | 17.0 | 67238 | MASTER-IAC | C | 180 | 16.7 | 67565 | MASTER-IAC | C | 60 | 16.7 | 67834 | MASTER-IAC | C | 60 | 16.7 | 67834 | MASTER-IAC | C | 60 | 16.2 | 67923 | MASTER-IAC | C | 60 | 16.0 | 68440 | MASTER-IAC | C | 180 | 16.9 | 68440 | MASTER-IAC | C | 180 | 16.6 | 68770 | MASTER-IAC | C | 60 | 16.4 | 69041 | MASTER-IAC | C | 60 | 16.5 | 69041 | MASTER-IAC | C | 60 | 16.0 | 69130 | MASTER-IAC | C | 60 | 15.7 | 69636 | MASTER-IAC | C | 180 | 16.6 | 69636 | MASTER-IAC | C | 180 | 16.3 | 69964 | MASTER-IAC | C | 60 | 16.2 | 70235 | MASTER-IAC | C | 60 | 16.4 | 70235 | MASTER-IAC | C | 60 | 15.8 | 70323 | MASTER-IAC | C | 60 | 15.5 | 70835 | MASTER-IAC | C | 180 | 16.4 | 70835 | MASTER-IAC | C | 180 | 15.9 | 71522 | MASTER-Kislovodsk | C | 180 | 16.5 | 71722 | MASTER-Kislovodsk | C | 180 | 16.1 | 72000 | MASTER-IAC | C | 180 | 16.1 | 72000 | MASTER-IAC | C | 180 | 16.0 | 73190 | MASTER-IAC | C | 180 | 15.8 | 73190 | MASTER-IAC | C | 180 | 15.9 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.