TITLE: GCN CIRCULAR NUMBER: 35427 SUBJECT: Fermi trigger No 725143760: Global MASTER-Net observations report DATE: 23/12/24 21:16:05 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru> V. Lipunov, V.Kornilov, E. Gorbovskoy, K. Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.Senik, D. Vlasenko, G.Antipov, D.Zimnukhov, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D. Cheryasov, Ya.Kechin, Yu.Tselik, A. Sosnovskij (Lomonosov Moscow State University, SAI, Physics Department), R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico Felix Aguilar OAFA), R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias), D. Buckley (South African Astronomical Observatory), O.A. Gress, N.M. Budnev, O.Ershova (Irkutsk State University, API), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), V. Yurkov, A. Gabovich (Blagoveschensk Educational State University) 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 GRB231224.87 (trigger No 725143760,06h 49m 09.60s , -71d 10m 12.0s, R=11.88) errorbox 348 sec after notice time and 390 sec after trigger time at 2023-12-24 20:55:46 UT, with upper limit up to 19.0 mag. The observations began at zenith distance = 36 deg. The sun altitude is -29.4 deg. The galactic latitude b = -26 deg., longitude l = 282 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2342087 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 420 | 2023-12-24 20:55:46 | MASTER-SAAO | (05h 53m 02.24s , -65d 19m 23.8s) | C | 60 | 17.9 | 420 | 2023-12-24 20:55:46 | MASTER-SAAO | (06h 13m 27.52s , -65d 30m 39.0s) | C | 60 | 18.1 | 511 | 2023-12-24 20:57:16 | MASTER-SAAO | (06h 03m 17.13s , -63d 24m 19.9s) | C | 60 | 18.3 | 511 | 2023-12-24 20:57:16 | MASTER-SAAO | (06h 22m 19.48s , -63d 35m 38.8s) | C | 60 | 18.6 | 590 | 2023-12-24 20:58:36 | MASTER-SAAO | (06h 21m 12.31s , -67d 12m 33.5s) | C | 60 | 18.1 | 590 | 2023-12-24 20:58:36 | MASTER-SAAO | (06h 43m 11.91s , -67d 23m 56.6s) | C | 60 | 18.4 | 681 | 2023-12-24 21:00:07 | MASTER-SAAO | (05h 41m 42.60s , -67d 14m 18.9s) | C | 60 | 17.3 | 681 | 2023-12-24 21:00:07 | MASTER-SAAO | (06h 03m 44.79s , -67d 25m 34.9s) | C | 60 | 17.6 | 765 | 2023-12-24 21:01:31 | MASTER-SAAO | (06h 29m 42.58s , -65d 19m 28.2s) | C | 60 | 19.0 | 765 | 2023-12-24 21:01:31 | MASTER-SAAO | (06h 50m 06.29s , -65d 30m 55.7s) | C | 60 | 18.7 | 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/35427. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...