TITLE: GCN CIRCULAR NUMBER: 35408 SUBJECT: Fermi trigger No 724781422: Global MASTER-Net observations report DATE: 23/12/20 17:46:09 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-Tunka robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Applied Physics Institute, Irkutsk State University) started inspect of the Fermi GRB231220.67 (trigger No 724781422,04h 53m 28.80s , +82d 17m 24.0s, R=5.04) errorbox 47 sec after notice time and 81 sec after trigger time at 2023-12-20 16:11:39 UT, with upper limit up to 19.6 mag. The observations began at zenith distance = 31 deg. The sun altitude is -60.6 deg.

MASTER-Kislovodsk robotic telescope located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the Fermi GRB231220.67 errorbox 111 sec after notice time and 146 sec after trigger time at 2023-12-20 16:12:43 UT, with upper limit up to 19.6 mag. The observations began at zenith distance = 44 deg. The sun altitude is -27.3 deg.

The galactic latitude b = 23 deg., longitude l = 130 deg.

Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2338295

We obtain a following upper limits.

Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________

92 | 2023-12-20 16:11:39 | MASTER-Tunka | (04h 50m 37.99s , +82d 29m 18.3s) | C | 20 | 18.9 | 117 | 2023-12-20 16:11:39 | MASTER-Tunka | (04h 50m 37.99s , +82d 29m 18.3s) | C | 70 | 19.6 | Coadd 177 | 2023-12-20 16:11:39 | MASTER-Tunka | (04h 50m 38.02s , +82d 29m 18.3s) | C | 190 | 19.5 | Coadd 116 | 2023-12-20 16:12:03 | MASTER-Tunka | (04h 50m 37.58s , +82d 29m 18.9s) | C | 20 | 19.0 | 145 | 2023-12-20 16:12:27 | MASTER-Tunka | (04h 50m 37.01s , +82d 29m 20.5s) | C | 30 | 19.2 | 161 | 2023-12-20 16:12:43 | MASTER-Kislovodsk | (05h 23m 52.17s , +82d 05m 38.2s) | C | 30 | 18.4 | 206 | 2023-12-20 16:12:43 | MASTER-Kislovodsk | (05h 23m 52.18s , +82d 05m 38.2s) | C | 120 | 19.4 | Coadd 391 | 2023-12-20 16:12:43 | MASTER-Kislovodsk | (05h 23m 52.15s , +82d 05m 38.2s) | C | 490 | 19.4 | Coadd 179 | 2023-12-20 16:13:00 | MASTER-Tunka | (04h 50m 36.68s , +82d 29m 21.6s) | C | 30 | 19.2 | 224 | 2023-12-20 16:13:00 | MASTER-Tunka | (04h 50m 36.71s , +82d 29m 21.6s) | C | 120 | 19.1 | Coadd 216 | 2023-12-20 16:13:33 | MASTER-Kislovodsk | (05h 23m 55.20s , +82d 06m 40.5s) | C | 40 | 18.8 | 218 | 2023-12-20 16:13:34 | MASTER-Tunka | (04h 50m 35.94s , +82d 29m 23.3s) | C | 40 | 18.3 | 266 | 2023-12-20 16:14:18 | MASTER-Tunka | (04h 50m 35.30s , +82d 29m 25.3s) | C | 50 | 18.4 | 283 | 2023-12-20 16:14:35 | MASTER-Kislovodsk | (05h 23m 57.88s , +82d 05m 45.2s) | C | 50 | 19.0 | 326 | 2023-12-20 16:15:13 | MASTER-Tunka | (04h 50m 34.17s , +82d 29m 28.2s) | C | 60 | 18.5 | 386 | 2023-12-20 16:15:13 | MASTER-Tunka | (04h 50m 34.19s , +82d 29m 28.2s) | C | 180 | 12.4 | Coadd 360 | 2023-12-20 16:15:47 | MASTER-Kislovodsk | (05h 23m 49.33s , +82d 04m 49.1s) | C | 60 | 19.0 | 515 | 2023-12-20 16:15:47 | MASTER-Kislovodsk | (05h 23m 49.29s , +82d 04m 49.1s) | C | 370 | 19.6 | Coadd 390 | 2023-12-20 16:16:16 | MASTER-Tunka | (04h 50m 33.23s , +82d 29m 30.4s) | C | 60 | 18.5 | 599 | 2023-12-20 16:19:46 | MASTER-Tunka | (04h 49m 16.45s , +82d 24m 30.5s) | C | 60 | 18.6 | 663 | 2023-12-20 16:20:50 | MASTER-Tunka | (04h 49m 15.45s , +82d 24m 32.6s) | C | 60 | 18.8 | 723 | 2023-12-20 16:20:50 | MASTER-Tunka | (04h 49m 15.47s , +82d 24m 32.5s) | C | 180 | 19.3 | Coadd 727 | 2023-12-20 16:21:54 | MASTER-Tunka | (04h 49m 14.41s , +82d 24m 34.9s) | C | 60 | 18.8 | 777 | 2023-12-20 16:22:04 | MASTER-Kislovodsk | (05h 22m 17.38s , +81d 58m 31.2s) | C | 140 | 19.2 | 791 | 2023-12-20 16:22:58 | MASTER-Tunka | (04h 49m 13.31s , +82d 24m 37.6s) | C | 60 | 18.8 | 953 | 2023-12-20 16:24:45 | MASTER-Kislovodsk | (05h 22m 25.64s , +81d 59m 51.5s) | C | 170 | 19.3 | 1149 | 2023-12-20 16:27:56 | MASTER-Kislovodsk | (05h 22m 17.42s , +81d 59m 23.7s) | C | 180 | 19.4 | 1291 | 2023-12-20 16:31:18 | MASTER-Kislovodsk | (04h 54m 53.65s , +82d 03m 55.3s) | C | 60 | 15.0 | 2595 | 2023-12-20 16:53:02 | MASTER-Kislovodsk | (04h 36m 40.50s , +82d 37m 42.1s) | C | 60 | 18.4 | 2675 | 2023-12-20 16:54:22 | MASTER-Kislovodsk | (06h 40m 35.82s , +82d 35m 35.2s) | C | 60 | 18.5 | 2757 | 2023-12-20 16:55:44 | MASTER-Kislovodsk | (06h 17m 17.19s , +84d 28m 19.6s) | C | 60 | 18.6 | 2839 | 2023-12-20 16:57:05 | MASTER-Kislovodsk | (05h 42m 20.32s , +78d 51m 06.7s) | C | 60 | 18.8 | 2921 | 2023-12-20 16:58:28 | MASTER-Kislovodsk | (05h 42m 52.38s , +78d 51m 07.7s) | C | 60 | 14.8 | 3001 | 2023-12-20 16:59:48 | MASTER-Kislovodsk | (05h 44m 09.29s , +78d 51m 11.1s) | C | 60 | 14.8 | 3082 | 2023-12-20 17:01:09 | MASTER-Kislovodsk | (03h 38m 32.79s , +80d 46m 42.5s) | C | 60 | 18.5 | 3163 | 2023-12-20 17:02:29 | MASTER-Kislovodsk | (03h 28m 26.96s , +84d 34m 57.7s) | C | 60 | 18.6 | 3244 | 2023-12-20 17:03:51 | MASTER-Kislovodsk | (05h 26m 07.87s , +86d 21m 38.1s) | C | 60 | 18.7 | 3324 | 2023-12-20 17:05:11 | MASTER-Kislovodsk | (07h 02m 56.70s , +78d 48m 04.5s) | C | 60 | 18.6 | 3406 | 2023-12-20 17:06:32 | MASTER-Kislovodsk | (04h 51m 59.60s , +76d 58m 32.8s) | C | 60 | 18.6 | 4959 | 2023-12-20 17:32:26 | MASTER-Kislovodsk | (05h 16m 05.81s , +80d 44m 30.6s) | C | 60 | 18.7 | 5040 | 2023-12-20 17:33:47 | MASTER-Kislovodsk | (04h 36m 36.25s , +82d 40m 42.7s) | C | 60 | 18.5 | Filter C is a clear (unfiltred) band.

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

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