Fermi GRB 241209C: Global MASTER-Net observations report

MASTER-Kislovodsk robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the Fermi GRB 241209C ( Fermi GBM team, GCN 38482) errorbox 41800 sec after notice time and 41825 sec after trigger time at 2024-12-09 18:59:59 UT, with upper limit up to 17.5 mag. The observations began at zenith distance = 76 deg. The sun altitude is -57.6 deg. The galactic latitude b = 12 deg., longitude l = 220 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2701134 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 41855 | 2024-12-09 18:59:59 | MASTER-Kislovodsk | (07h 45m 09.49s , -00d 33m 01.9s) | C | 60 | 16.5 | 41935 | 2024-12-09 19:01:19 | MASTER-Kislovodsk | (07h 53m 08.72s , -00d 32m 20.8s) | C | 60 | 16.9 | 42097 | 2024-12-09 19:04:01 | MASTER-Kislovodsk | (07h 45m 10.51s , -00d 34m 01.9s) | C | 60 | 17.3 | 42177 | 2024-12-09 19:05:21 | MASTER-Kislovodsk | (07h 53m 14.71s , -00d 34m 16.8s) | C | 60 | 16.9 | 42339 | 2024-12-09 19:08:03 | MASTER-Kislovodsk | (07h 45m 12.59s , -00d 33m 47.5s) | C | 60 | 16.8 | 42418 | 2024-12-09 19:09:22 | MASTER-Kislovodsk | (07h 29m 57.54s , -00d 32m 27.7s) | C | 60 | 17.3 | 42497 | 2024-12-09 19:10:42 | MASTER-Kislovodsk | (07h 37m 56.59s , -00d 31m 43.1s) | C | 60 | 17.5 | 42656 | 2024-12-09 19:13:21 | MASTER-Kislovodsk | (07h 37m 57.58s , -00d 33m 39.4s) | C | 60 | 17.5 | 42736 | 2024-12-09 19:14:40 | MASTER-Kislovodsk | (07h 30m 03.51s , -00d 33m 16.2s) | C | 60 | 17.3 | 42982 | 2024-12-09 19:18:46 | MASTER-Kislovodsk | (07h 53m 15.57s , -00d 32m 07.6s) | C | 60 | 16.9 | 43228 | 2024-12-09 19:22:52 | MASTER-Kislovodsk | (07h 53m 15.43s , -00d 32m 37.7s) | C | 60 | 16.8 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.