TITLE: GCN CIRCULAR NUMBER: 41880 SUBJECT: EP250919a: Global MASTER-Net observations report DATE: 25/09/19 04:54:19 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru> V.Lipunov, E.Gorbovskoy, A.Kuznetsov, K.Zhirkov, I.Panchenko, N.Tiurina, P.Balanutsa, V.Topolev, D.Vlasenko, G.Antipov, A.Sankovich, Yu.Tselik, 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.Sosnovskij (CrAO), 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-OAFA robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Argentina (OAFA observatory of San Juan National University) was pointed to the EP250919a ( EP Team et al., GCN 41879) errorbox 1286 sec after trigger time at 2025-09-19 02:36:21 UT, with upper limit up to 20.4 mag. The observations began at zenith distance = 28 deg. The sun altitude is -50.4 deg. MASTER-SAAO robotic telescope located in South Africa (South African Astronomical Observatory) was pointed to the EP250919a errorbox 2640 sec after trigger time at 2025-09-19 02:58:55 UT, with upper limit up to 17.7 mag. The observations began at zenith distance = 85 deg. The sun altitude is -20.6 deg. The galactic latitude b = -31 deg., longitude l = 350 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2994829 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 1317 | 2025-09-19 02:36:21 | MASTER-OAFA | (20h 01m 51.73s , -50d 10m 08.0s) | C | 60 | 20.4 | 1393 | 2025-09-19 02:37:38 | MASTER-OAFA | (20h 01m 45.42s , -50d 11m 06.5s) | C | 60 | 20.4 | 1468 | 2025-09-19 02:38:53 | MASTER-OAFA | (20h 01m 51.69s , -50d 11m 05.3s) | C | 60 | 20.4 | 1771 | 2025-09-19 02:43:56 | MASTER-OAFA | (20h 02m 12.87s , -48d 15m 58.0s) | C | 60 | 20.3 | 1848 | 2025-09-19 02:45:13 | MASTER-OAFA | (20h 02m 12.38s , -48d 14m 56.9s) | C | 60 | 20.3 | 1923 | 2025-09-19 02:46:28 | MASTER-OAFA | (20h 02m 18.99s , -48d 15m 56.3s) | C | 60 | 20.3 | 2652 | 2025-09-19 02:58:37 | MASTER-OAFA | (19h 53m 50.03s , -48d 54m 47.0s) | C | 60 | 20.1 | 2671 | 2025-09-19 02:58:55 | MASTER-SAAO | (19h 53m 22.97s , -48d 53m 39.0s) | C | 60 | 17.3 | 2731 | 2025-09-19 02:58:55 | MASTER-SAAO | (19h 53m 23.03s , -48d 53m 39.6s) | C | 180 | 17.7 | Coadd 2718 | 2025-09-19 02:59:42 | MASTER-OAFA | (19h 53m 50.12s , -48d 54m 46.3s) | C | 60 | 20.2 | 2750 | 2025-09-19 03:00:14 | MASTER-SAAO | (19h 53m 22.90s , -48d 53m 35.3s) | C | 60 | 17.2 | 2783 | 2025-09-19 03:00:48 | MASTER-OAFA | (19h 53m 50.30s , -48d 54m 45.8s) | C | 60 | 20.2 | 2829 | 2025-09-19 03:01:33 | MASTER-SAAO | (19h 53m 22.92s , -48d 53m 29.8s) | C | 60 | 16.4 | 2849 | 2025-09-19 03:01:54 | MASTER-OAFA | (19h 53m 50.44s , -48d 54m 45.2s) | C | 60 | 20.2 | 2908 | 2025-09-19 03:02:52 | MASTER-SAAO | (19h 53m 22.65s , -48d 53m 20.6s) | C | 60 | 17.0 | 2915 | 2025-09-19 03:02:59 | MASTER-OAFA | (19h 53m 50.57s , -48d 54m 44.6s) | C | 60 | 20.3 | 2980 | 2025-09-19 03:04:05 | MASTER-OAFA | (19h 53m 50.70s , -48d 54m 43.9s) | C | 60 | 20.3 | 3047 | 2025-09-19 03:05:11 | MASTER-OAFA | (19h 53m 50.85s , -48d 54m 43.5s) | C | 60 | 20.3 | 3112 | 2025-09-19 03:06:17 | MASTER-OAFA | (19h 53m 51.00s , -48d 54m 43.3s) | C | 60 | 20.2 | 3178 | 2025-09-19 03:07:22 | MASTER-OAFA | (19h 53m 51.10s , -48d 54m 42.9s) | C | 60 | 20.2 | 3244 | 2025-09-19 03:08:29 | MASTER-OAFA | (19h 53m 51.26s , -48d 54m 42.6s) | C | 60 | 20.2 | 3310 | 2025-09-19 03:09:34 | MASTER-OAFA | (19h 53m 51.38s , -48d 54m 42.1s) | C | 60 | 20.3 | 3375 | 2025-09-19 03:10:39 | MASTER-OAFA | (19h 53m 51.55s , -48d 54m 41.6s) | C | 60 | 20.2 | 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/41880. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...