TITLE: GCN CIRCULAR NUMBER: 41556 SUBJECT: EP250827a: Global MASTER-Net observations report DATE: 25/08/27 09:18:21 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 EP250827a ( EP Team et al., GCN 41553) errorbox 371 sec after trigger time at 2025-08-27 07:46:54 UT, with upper limit up to 21.0 mag. The observations began at zenith distance = 29 deg. The sun altitude is -41.2 deg. The galactic latitude b = -60 deg., longitude l = 313 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2978010 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 407 | 2025-08-27 07:46:54 | MASTER-OAFA | (00h 13m 54.06s , -56d 38m 35.7s) | C | 70 | 20.5 | 492 | 2025-08-27 07:48:10 | MASTER-OAFA | (00h 13m 54.34s , -56d 38m 33.9s) | C | 90 | 20.7 | 599 | 2025-08-27 07:49:46 | MASTER-OAFA | (00h 13m 54.64s , -56d 38m 32.6s) | C | 110 | 20.8 | 680 | 2025-08-27 07:51:43 | MASTER-OAFA | (00h 13m 54.87s , -56d 38m 31.2s) | C | 40 | 20.2 | 726 | 2025-08-27 07:52:29 | MASTER-OAFA | (00h 13m 55.02s , -56d 38m 30.5s) | C | 40 | 20.2 | 772 | 2025-08-27 07:53:14 | MASTER-OAFA | (00h 13m 55.19s , -56d 38m 29.9s) | C | 40 | 20.3 | 817 | 2025-08-27 07:54:00 | MASTER-OAFA | (00h 13m 55.31s , -56d 38m 29.1s) | C | 40 | 20.2 | 863 | 2025-08-27 07:54:46 | MASTER-OAFA | (00h 13m 55.44s , -56d 38m 28.5s) | C | 40 | 20.2 | 909 | 2025-08-27 07:55:31 | MASTER-OAFA | (00h 13m 55.59s , -56d 38m 27.9s) | C | 40 | 20.3 | 955 | 2025-08-27 07:56:18 | MASTER-OAFA | (00h 13m 55.72s , -56d 38m 27.0s) | C | 40 | 20.2 | 995 | 2025-08-27 07:56:18 | MASTER-OAFA | (00h 13m 55.72s , -56d 38m 27.0s) | C | 120 | 20.9 | Coadd 1001 | 2025-08-27 07:57:03 | MASTER-OAFA | (00h 13m 55.84s , -56d 38m 26.2s) | C | 40 | 20.2 | 1046 | 2025-08-27 07:57:49 | MASTER-OAFA | (00h 13m 55.97s , -56d 38m 25.7s) | C | 40 | 20.2 | 1093 | 2025-08-27 07:58:35 | MASTER-OAFA | (00h 13m 56.15s , -56d 38m 25.0s) | C | 40 | 20.2 | 1133 | 2025-08-27 07:58:35 | MASTER-OAFA | (00h 13m 56.15s , -56d 38m 25.0s) | C | 120 | 21.0 | Coadd 1138 | 2025-08-27 07:59:21 | MASTER-OAFA | (00h 13m 56.27s , -56d 38m 24.5s) | C | 40 | 20.2 | 1184 | 2025-08-27 08:00:06 | MASTER-OAFA | (00h 13m 56.41s , -56d 38m 23.7s) | C | 40 | 20.3 | 1230 | 2025-08-27 08:00:52 | MASTER-OAFA | (00h 13m 56.58s , -56d 38m 23.2s) | C | 40 | 20.2 | 1270 | 2025-08-27 08:00:52 | MASTER-OAFA | (00h 13m 56.57s , -56d 38m 23.2s) | C | 120 | 21.0 | Coadd 1276 | 2025-08-27 08:01:38 | MASTER-OAFA | (00h 13m 56.69s , -56d 38m 22.7s) | C | 40 | 20.2 | 1321 | 2025-08-27 08:02:24 | MASTER-OAFA | (00h 13m 56.85s , -56d 38m 21.8s) | C | 40 | 20.2 | 1367 | 2025-08-27 08:03:10 | MASTER-OAFA | (00h 13m 56.98s , -56d 38m 21.1s) | C | 40 | 20.2 | 1413 | 2025-08-27 08:03:55 | MASTER-OAFA | (00h 13m 57.14s , -56d 38m 20.5s) | C | 40 | 20.2 | 1458 | 2025-08-27 08:04:40 | MASTER-OAFA | (00h 13m 57.27s , -56d 38m 19.9s) | C | 40 | 20.2 | 1504 | 2025-08-27 08:05:26 | MASTER-OAFA | (00h 13m 57.42s , -56d 38m 19.4s) | C | 40 | 20.2 | 1544 | 2025-08-27 08:05:26 | MASTER-OAFA | (00h 13m 57.42s , -56d 38m 19.4s) | C | 120 | 21.0 | Coadd 1549 | 2025-08-27 08:06:12 | MASTER-OAFA | (00h 13m 57.57s , -56d 38m 18.6s) | C | 40 | 20.2 | 1595 | 2025-08-27 08:06:58 | MASTER-OAFA | (00h 13m 57.70s , -56d 38m 18.1s) | C | 40 | 20.2 | 1642 | 2025-08-27 08:07:44 | MASTER-OAFA | (00h 13m 57.88s , -56d 38m 17.5s) | C | 40 | 20.2 | 1687 | 2025-08-27 08:08:30 | MASTER-OAFA | (00h 13m 58.02s , -56d 38m 17.0s) | C | 40 | 20.1 | 1732 | 2025-08-27 08:09:15 | MASTER-OAFA | (00h 13m 58.16s , -56d 38m 16.4s) | C | 40 | 20.1 | 3986 | 2025-08-27 08:46:38 | MASTER-OAFA | (00h 14m 05.29s , -56d 37m 56.2s) | C | 60 | 19.4 | 4046 | 2025-08-27 08:46:38 | MASTER-OAFA | (00h 14m 05.29s , -56d 37m 56.2s) | C | 180 | 20.0 | Coadd 4061 | 2025-08-27 08:47:53 | MASTER-OAFA | (00h 14m 08.12s , -56d 36m 11.6s) | C | 60 | 19.3 | 4137 | 2025-08-27 08:49:10 | MASTER-OAFA | (00h 14m 03.64s , -56d 37m 03.5s) | C | 60 | 19.3 | 4215 | 2025-08-27 08:50:28 | MASTER-OAFA | (00h 14m 02.43s , -56d 36m 02.5s) | C | 60 | 19.3 | 4275 | 2025-08-27 08:50:28 | MASTER-OAFA | (00h 14m 02.43s , -56d 36m 02.5s) | C | 180 | 20.0 | Coadd 4291 | 2025-08-27 08:51:43 | MASTER-OAFA | (00h 14m 10.29s , -56d 37m 02.2s) | C | 60 | 19.4 | 4369 | 2025-08-27 08:53:01 | MASTER-OAFA | (00h 14m 02.79s , -56d 38m 01.6s) | C | 60 | 19.5 | 4447 | 2025-08-27 08:54:19 | MASTER-OAFA | (00h 14m 09.55s , -56d 37m 48.8s) | C | 60 | 19.4 | 4525 | 2025-08-27 08:55:37 | MASTER-OAFA | (00h 14m 07.17s , -56d 36m 15.0s) | C | 60 | 19.3 | 4599 | 2025-08-27 08:56:51 | MASTER-OAFA | (00h 14m 07.39s , -56d 37m 46.8s) | C | 60 | 19.3 | 4674 | 2025-08-27 08:58:07 | MASTER-OAFA | (00h 14m 10.80s , -56d 36m 08.9s) | C | 60 | 19.4 | 4750 | 2025-08-27 08:59:23 | MASTER-OAFA | (00h 14m 04.33s , -56d 36m 58.4s) | C | 60 | 19.4 | 4827 | 2025-08-27 09:00:39 | MASTER-OAFA | (00h 14m 05.93s , -56d 35m 57.5s) | C | 60 | 19.4 | 4900 | 2025-08-27 09:02:02 | MASTER-OAFA | (00h 14m 10.40s , -56d 36m 57.1s) | C | 40 | 20.2 | 4945 | 2025-08-27 09:02:48 | MASTER-OAFA | (00h 14m 10.58s , -56d 36m 56.9s) | C | 40 | 20.2 | 4991 | 2025-08-27 09:03:33 | MASTER-OAFA | (00h 14m 10.70s , -56d 36m 56.6s) | C | 40 | 20.1 | 5047 | 2025-08-27 09:04:30 | MASTER-OAFA | (00h 14m 04.87s , -56d 37m 56.3s) | C | 40 | 20.1 | 5093 | 2025-08-27 09:05:16 | MASTER-OAFA | (00h 14m 05.01s , -56d 37m 55.8s) | C | 40 | 20.1 | 5138 | 2025-08-27 09:06:01 | MASTER-OAFA | (00h 14m 05.17s , -56d 37m 55.6s) | C | 40 | 20.1 | 5193 | 2025-08-27 09:06:55 | MASTER-OAFA | (00h 14m 11.73s , -56d 37m 28.0s) | C | 40 | 20.1 | 5238 | 2025-08-27 09:07:41 | MASTER-OAFA | (00h 14m 11.89s , -56d 37m 27.8s) | C | 40 | 20.2 | 5284 | 2025-08-27 09:08:26 | MASTER-OAFA | (00h 14m 12.04s , -56d 37m 27.5s) | C | 40 | 20.2 | 5342 | 2025-08-27 09:09:25 | MASTER-OAFA | (00h 14m 09.80s , -56d 36m 14.9s) | C | 40 | 20.2 | 5388 | 2025-08-27 09:10:10 | MASTER-OAFA | (00h 14m 09.96s , -56d 36m 14.4s) | C | 40 | 20.1 | 5433 | 2025-08-27 09:10:56 | MASTER-OAFA | (00h 14m 10.12s , -56d 36m 14.4s) | C | 40 | 20.1 | 5489 | 2025-08-27 09:11:52 | MASTER-OAFA | (00h 14m 10.28s , -56d 37m 47.0s) | C | 40 | 20.1 | 5535 | 2025-08-27 09:12:37 | MASTER-OAFA | (00h 14m 10.41s , -56d 37m 46.7s) | C | 40 | 20.1 | 5580 | 2025-08-27 09:13:23 | MASTER-OAFA | (00h 14m 10.58s , -56d 37m 46.4s) | C | 40 | 20.2 | 5637 | 2025-08-27 09:14:19 | MASTER-OAFA | (00h 14m 12.90s , -56d 35m 55.2s) | C | 40 | 20.1 | 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/41556. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...