Fermi GRB 240504A: Global MASTER-Net observations report

MASTER-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB 240504A ( Fermi GBM team, GCN 36387) errorbox 42875 sec after notice time and 42910 sec after trigger time at 2024-05-04 17:08:02 UT, with upper limit up to 17.4 mag. Observations started at twilight. The observations began at zenith distance = 74 deg. The sun altitude is -15.3 deg. The galactic latitude b = -35 deg., longitude l = 200 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2442874 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 42940 | 2024-05-04 17:08:02 | MASTER-SAAO | (04h 16m 43.98s , -08d 23m 19.2s) | C | 60 | 17.3 | 43659 | 2024-05-04 17:20:01 | MASTER-SAAO | (04h 24m 57.17s , -08d 24m 29.7s) | C | 60 | 17.4 | 43979 | 2024-05-04 17:25:21 | MASTER-SAAO | (04h 17m 03.18s , -08d 23m 43.8s) | C | 60 | 16.9 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.