TITLE: GCN CIRCULAR NUMBER: 39070 SUBJECT: Swift GRB 250129A: Global MASTER-Net observations report DATE: 25/01/29 06:16:44 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-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 Swift GRB 250129A ( A. P. Beardmore et al., GCN 39066) errorbox 160 sec after notice time and 240 sec after trigger time at 2025-01-29 04:49:09 UT, with upper limit up to 20.7 mag. The observations began at zenith distance = 73 deg. The sun altitude is -41.0 deg.

The galactic latitude b = 67 deg., longitude l = 319 deg.

Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2760138

We obtain a following upper limits.

Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________

266 | MASTER-OAFA | C | 50 | 18.7 | 331 | MASTER-OAFA | C | 180 | 19.6 | Coadd 496 | MASTER-OAFA | C | 510 | 20.0 | Coadd 327 | MASTER-OAFA | C | 60 | 18.8 | 398 | MASTER-OAFA | C | 70 | 19.0 | 484 | MASTER-OAFA | C | 90 | 19.1 | 604 | MASTER-OAFA | C | 330 | 19.8 | Coadd 590 | MASTER-OAFA | C | 110 | 19.3 | 716 | MASTER-OAFA | C | 130 | 19.3 | 867 | MASTER-OAFA | C | 160 | 19.4 | 1043 | MASTER-OAFA | C | 180 | 19.5 | 1230 | MASTER-OAFA | C | 180 | 19.6 | 1417 | MASTER-OAFA | C | 180 | 19.6 | 1603 | MASTER-OAFA | C | 180 | 19.7 | 1789 | MASTER-OAFA | C | 180 | 19.8 | 1975 | MASTER-OAFA | C | 180 | 19.8 | 2155 | MASTER-OAFA | C | 540 | 20.2 | Coadd 2161 | MASTER-OAFA | C | 180 | 19.8 | 2347 | MASTER-OAFA | C | 180 | 19.8 | 2534 | MASTER-OAFA | C | 180 | 20.0 | 2714 | MASTER-OAFA | C | 540 | 20.3 | Coadd 2720 | MASTER-OAFA | C | 180 | 20.0 | 2906 | MASTER-OAFA | C | 180 | 20.0 | 3092 | MASTER-OAFA | C | 180 | 20.0 | 3272 | MASTER-OAFA | C | 540 | 20.7 | Coadd 3279 | MASTER-OAFA | C | 180 | 20.1 | 3465 | MASTER-OAFA | C | 180 | 20.1 | 3651 | MASTER-OAFA | C | 180 | 20.2 | 3831 | MASTER-OAFA | C | 540 | 20.7 | Coadd 3838 | MASTER-OAFA | C | 180 | 20.1 | 4024 | MASTER-OAFA | C | 180 | 20.1 | 4210 | MASTER-OAFA | C | 180 | 20.2 | 4397 | MASTER-OAFA | C | 180 | 20.2 | 4583 | MASTER-OAFA | C | 180 | 19.9 | 4769 | MASTER-OAFA | C | 180 | 20.3 | 4955 | MASTER-OAFA | C | 180 | 19.7 | Filter C is a clear (unfiltred) band.

The observation and reduction will continue. The message may be cited.

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