TITLE: GCN CIRCULAR NUMBER: 39358 SUBJECT: Fermi GRB 250217C: Global MASTER-Net observations report DATE: 25/02/18 00:16:58 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru> V.Lipunov, E.Gorbovskoy, N.Tiurina, P.Balanutsa, , D.Vlasenko, I.Panchenko, A.Kuznetsov, G.Antipov, A.Sankovich, A.Sosnovskij, Yu.Tselik, M.Gulyaev, Ya.Kechin, V.Senik, A.Chasovnikov, K.Labsina, I. Gorbunov (Lomonosov MSU), O.Gress, N.Budnev (ISU), C.Francile, F. Podesta, R.Podesta, E. Gonzalez (Observatorio Astronomico Felix Aguilar (OAFA), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity) D.Buckley (SAAO), R.Rebolo (The Instituto de Astrofisica de Canarias), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory) 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 250217C ( Fermi GBM team, GCN 39357) errorbox 588 sec after notice time and 626 sec after trigger time at 2025-02-18 00:05:08 UT, with upper limit up to 18.5 mag. The observations began at zenith distance = 74 deg. The sun altitude is -42.9 deg. The galactic latitude b = 38 deg., longitude l = 191 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2781342 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 657 | 2025-02-18 00:05:08 | MASTER-SAAO | (08h 45m 43.52s , +32d 50m 06.0s) | C | 60 | 17.9 | 717 | 2025-02-18 00:05:08 | MASTER-SAAO | (08h 45m 43.52s , +32d 50m 05.9s) | C | 180 | 18.5 | Coadd 736 | 2025-02-18 00:06:27 | MASTER-SAAO | (08h 45m 43.62s , +32d 50m 10.7s) | C | 60 | 17.6 | 815 | 2025-02-18 00:07:46 | MASTER-SAAO | (08h 45m 43.81s , +32d 50m 10.7s) | C | 60 | 17.5 | 894 | 2025-02-18 00:09:05 | MASTER-SAAO | (08h 45m 44.00s , +32d 50m 14.7s) | C | 60 | 17.6 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. View this GCN Circular online at https://gcn.nasa.gov/circulars/39358. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...