TITLE: GCN CIRCULAR NUMBER: 23466 SUBJECT: Short-duration GRB 181121.4: MASTER-Tavrida possible OT detection near the PGC galaxy during large Fermi error box inspection DATE: 18/11/27 18:03:57 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D. Vlasenko, T.Pogrosheva, I.Gorbunov, A.Chasovnikov Lomonosov Moscow State University, Sternberg Astronomical Institute D.Svinkin (Ioffe Institute, St Petergburg, Russia) R. Podesta, F. Podesta, C. Lopez, C.Francile Observatorio Astronomico Felix Aguilar (OAFA) Hugo Levato Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE) R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres The Instituto de Astrofisica de Canarias D. Buckley, South African Astronomical Observatory A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov Kislovodsk Solar Station of the Pulkovo Observatory O. Gres, N.M. Budnev, Yu.Ishmuhametova Applied Physics Institute of Irkutsk State University V. Yurkov, A. Gabovich, Yu. Sergienko Blagoveschensk Educational State University, Blagoveschensk MASTER-Tavrida robotic telescope located in Russia (Lomonosov MSU, SAI Crimea astronomical station) was pointed to the FERMI TRIGGER_NUM: 564485824 (possible GRB 181121.40) 1 days 61648 sec after trigger time at 2018-11-23 02:44:28 UT, with upper limit up to 19.1 mag. The observations began at zenit distance = 79 deg. The sun altitude is -21.8 deg. MASTER-Tavrida auto-detection system discovered possible OT source at (RA, Dec) = 17h 17m 38.71s +56d 56m 48.7s on 2018-11-23.87034 UT. Error is about 2 arcsec. The OT unfiltered magnitude is 17.7m (3 sigma limit 18.0 m). The OT is inside the large IPN box formed by intersection of the Fermi-INTEGRAL triangulation annulus and the Fermi-GBM 3 sigma final position (D. Svinkin, private communication). The OT is seen in 2 images. There is no minor planet at this place. We have reference image without OT on 2017-10-04.75208 UT with unfiltered magnitude limit 19.0m. The OT offset are 10.3E and 36N arc sec from center of the PGC3135767 galaxy. The distance to the Galaxy is about 120 Mpc for H = 70 km/s/Mpc . The absolute OT magnitude for this distance is about -17.8 . We reobserved this error-box in MASTER-Kislovodsk with mlim=20.4 , starting on 2018-11-26 16:17:29UT (1980s exp). We can not exclude OT m ~ 20.5 mag. MASTER-Amur robotic telescope (MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Blagoveshchensk State Pedagogical University) was pointed to the FERMI GRB181121.4 ( 16h 45m 52.80s , +37d 34m 48.00s, R=8) 43375 sec after trigger time at 2018-11-21 21:39:54 UT, with upper limit up to 17.4 mag. Observations started at twilight. The observations began at zenit distance = 67 deg. The sun altitude is -11.6 deg. MASTER-Tunka robotic telescope located in Russia (Applied Physics Institute, Irkutsk State University) was pointed to the FERMI GRB181121.4 1 days 4810 sec after trigger time at 2018-11-22 10:57:09 UT, with upper limit up to 18.2 mag. Observations started at twilight. The observations began at zenit distance = 54 deg. The sun altitude is -16.1 deg. MASTER-Kislovodsk robotic telescope located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) was pointed to the FERMI GRB181121.4 2 days 18064 sec after trigger time at 2018-11-23 14:38:04 UT, with upper limit up to 18.7 mag. Observations started at twilight. The observations began at zenit distance = 54 deg. The sun altitude is -10.4 deg. MASTER-IAC robotic telescope located in Spain (IAC Teide Observatory) was pointed to the FERMI GRB181121.4 4 days 34252 sec after trigger time at 2018-11-25 19:07:51 UT, with upper limit up to 17.9 mag. Observations started at twilight. The observations began at zenit distance = 69 deg. The sun altitude is -13.4 deg. The galactic latitude b = -60 deg., longitude l = 98 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=863199 We obtain a following upper limits. Tmid-T0 | Site | Coord (J2000) |Filt.| Expt. | Limit | Comment _________|_____________________|___________________________________|_____|_______|_______|________ 65063 | MASTER-Amur | ( 16h 43m 53.5s , +36d 0m 49.2s) | C | 180 | 16.03 | 65379 | MASTER-Amur | ( 16h 49m 33.2s , +35d 57m 24.8s) | C | 180 | 15.90 | 65770 | MASTER-Amur | ( 16h 43m 41.0s , +35d 59m 60.0s) | C | 180 | 0.00 | 66163 | MASTER-Amur | ( 16h 25m 48.0s , +32d 0m 10.0s) | C | 180 | 0.00 | 66981 | MASTER-Amur | ( 16h 25m 48.0s , +32d 0m 10.0s) | C | 60 | 0.00 | 67253 | MASTER-Amur | ( 16h 25m 48.0s , +32d 0m 10.0s) | C | 1 | 0.00 | 67559 | MASTER-Amur | ( 16h 25m 48.0s , +32d 0m 10.0s) | C | 10 | 0.00 | 68268 | MASTER-Amur | ( 16h 25m 48.0s , +32d 0m 10.0s) | C | 180 | 0.00 | 93615 | MASTER-Tunka | ( 17h 10m 00.9s , +30d 1m 50.4s) | C | 180 | 16.87 | 93615 | MASTER-Tunka | ( 17h 10m 00.9s , +30d 1m 50.4s) | C | 540 | 17.74 | Coadd 93990 | MASTER-Tunka | ( 17h 10m 00.9s , +30d 1m 22.5s) | C | 180 | 17.13 | 94362 | MASTER-Tunka | ( 17h 20m 53.7s , +31d 50m 10.1s) | C | 180 | 17.02 | 94362 | MASTER-Tunka | ( 17h 13m 02.3s , +32d 1m 14.6s) | C | 180 | 17.17 | 94707 | MASTER-Tunka | ( 17h 6m 10.5s , +33d 50m 40.4s) | C | 180 | 17.02 | 94707 | MASTER-Tunka | ( 16h 58m 08.4s , +34d 1m 44.1s) | C | 180 | 17.23 | 95112 | MASTER-Tunka | ( 17h 10m 00.3s , +30d 1m 28.6s) | C | 180 | 17.24 | 95514 | MASTER-Tunka | ( 17h 11m 48.4s , +35d 50m 07.6s) | C | 180 | 17.20 | 95517 | MASTER-Tunka | ( 17h 3m 34.1s , +36d 1m 11.6s) | C | 180 | 17.36 | 95890 | MASTER-Tunka | ( 17h 20m 52.6s , +31d 49m 55.0s) | C | 180 | 17.28 | 95891 | MASTER-Tunka | ( 17h 13m 01.4s , +32d 0m 58.5s) | C | 180 | 17.42 | 96314 | MASTER-Tunka | ( 17h 6m 09.8s , +33d 50m 31.4s) | C | 180 | 17.51 | 96314 | MASTER-Tunka | ( 16h 58m 08.0s , +34d 1m 34.3s) | C | 180 | 17.84 | 96705 | MASTER-Tunka | ( 17h 31m 35.5s , +35d 49m 59.6s) | C | 180 | 17.77 | 96705 | MASTER-Tunka | ( 17h 23m 21.0s , +36d 1m 04.0s) | C | 180 | 17.93 | 97087 | MASTER-Tunka | ( 17h 11m 47.7s , +35d 50m 01.3s) | C | 180 | 17.61 | 97088 | MASTER-Tunka | ( 17h 3m 33.8s , +36d 1m 05.5s) | C | 180 | 17.90 | 97791 | MASTER-Tunka | ( 17h 30m 54.3s , +38d 1m 12.1s) | C | 180 | 18.18 | 98164 | MASTER-Tunka | ( 17h 31m 34.2s , +35d 49m 35.3s) | C | 180 | 17.75 | 98165 | MASTER-Tunka | ( 17h 23m 21.1s , +36d 0m 57.2s) | C | 180 | 17.84 | 98536 | MASTER-Tunka | ( 17h 28m 00.3s , +39d 49m 37.0s) | C | 180 | 17.93 | 98539 | MASTER-Tunka | ( 17h 19m 19.0s , +40d 0m 59.4s) | C | 180 | 18.20 | 98817 | MASTER-Amur | ( 17h 19m 51.0s , +44d 0m 07.0s) | C | 180 | 0.00 | 98916 | MASTER-Tunka | ( 17h 29m 51.1s , +42d 1m 04.5s) | C | 180 | 17.99 | 99133 | MASTER-Amur | ( 17h 19m 50.0s , +44d 0m 07.0s) | C | 180 | 0.00 | 99306 | MASTER-Tunka | ( 17h 30m 53.9s , +38d 1m 00.7s) | C | 180 | 18.00 | 99452 | MASTER-Amur | ( 17h 12m 56.5s , +43d 53m 51.5s) | C | 180 | 16.65 | 99705 | MASTER-Tunka | ( 16h 46m 47.4s , +33d 50m 16.8s) | C | 180 | 17.21 | 99705 | MASTER-Tunka | ( 16h 38m 48.1s , +34d 1m 39.3s) | C | 180 | 17.32 | 100061 | MASTER-Tunka | ( 17h 27m 59.5s , +39d 49m 26.0s) | C | 180 | 17.83 | 100061 | MASTER-Tunka | ( 17h 19m 18.6s , +40d 0m 49.4s) | C | 180 | 18.02 | 100446 | MASTER-Tunka | ( 17h 29m 50.7s , +42d 0m 54.8s) | C | 180 | 17.90 | 100791 | MASTER-Tunka | ( 17h 25m 24.9s , +33d 49m 44.6s) | C | 180 | 17.49 | 100791 | MASTER-Tunka | ( 17h 17m 24.5s , +34d 1m 06.3s) | C | 180 | 17.67 | 101157 | MASTER-Tunka | ( 16h 46m 46.9s , +33d 50m 04.9s) | C | 180 | 17.10 | 101157 | MASTER-Tunka | ( 16h 38m 47.7s , +34d 1m 26.5s) | C | 180 | 17.34 | 102296 | MASTER-Tunka | ( 17h 25m 23.7s , +33d 49m 34.6s) | C | 180 | 17.40 | 102297 | MASTER-Tunka | ( 17h 17m 24.5s , +34d 0m 56.9s) | C | 180 | 17.45 | 147389 | MASTER-Amur | ( 16h 5m 15.5s , +37d 57m 01.2s) | C | 180 | 17.06 | 147703 | MASTER-Amur | ( 16h 15m 24.3s , +37d 56m 40.1s) | C | 180 | 16.85 | 148028 | MASTER-Amur | ( 16h 25m 33.9s , +37d 56m 30.4s) | C | 180 | 16.71 | 149052 | MASTER-Amur | ( 16h 29m 34.1s , +35d 57m 16.8s) | C | 180 | 16.45 | 149472 | MASTER-Amur | ( 16h 35m 40.5s , +37d 57m 21.7s) | C | 180 | 16.77 | 149789 | MASTER-Amur | ( 16h 45m 49.5s , +37d 57m 14.2s) | C | 180 | 16.74 | 150106 | MASTER-Amur | ( 16h 22m 29.3s , +39d 57m 42.6s) | C | 180 | 17.02 | 150418 | MASTER-Amur | ( 16h 22m 30.7s , +39d 57m 48.8s) | C | 180 | 17.02 | 150757 | MASTER-Amur | ( 16h 32m 56.1s , +39d 57m 48.3s) | C | 180 | 17.03 | 178873 | MASTER-Tavrida | ( 16h 20m 20.9s , +32d 3m 13.6s) | C | 180 | 16.65 | 178873 | MASTER-Tavrida | ( 16h 21m 56.5s , +32d 2m 24.8s) | C | 180 | 17.25 | 180177 | MASTER-Tavrida | ( 16h 20m 01.0s , +30d 2m 02.2s) | C | 180 | 17.42 | 180177 | MASTER-Tavrida | ( 16h 18m 27.7s , +30d 2m 47.8s) | C | 180 | 16.44 | 180503 | MASTER-Tavrida | ( 16h 21m 56.4s , +32d 2m 03.5s) | C | 180 | 17.47 | 180503 | MASTER-Tavrida | ( 16h 20m 21.2s , +32d 2m 49.1s) | C | 180 | 16.84 | 181152 | MASTER-Tavrida | ( 16h 39m 14.8s , +32d 2m 43.2s) | C | 180 | 16.71 | 181152 | MASTER-Tavrida | ( 16h 40m 50.1s , +32d 1m 55.2s) | C | 180 | 17.24 | 181476 | MASTER-Tavrida | ( 16h 38m 29.9s , +30d 1m 33.7s) | C | 180 | 17.39 | 181477 | MASTER-Tavrida | ( 16h 36m 56.5s , +30d 2m 22.1s) | C | 180 | 16.57 | 182491 | MASTER-Tavrida | ( 16h 20m 02.2s , +30d 2m 26.6s) | C | 180 | 17.31 | 182820 | MASTER-Tavrida | ( 16h 40m 48.9s , +32d 2m 04.8s) | C | 180 | 17.31 | 182820 | MASTER-Tavrida | ( 16h 39m 13.8s , +32d 2m 45.2s) | C | 180 | 16.71 | 183146 | MASTER-Tavrida | ( 16h 38m 30.0s , +30d 1m 24.2s) | C | 180 | 17.40 | 183146 | MASTER-Tavrida | ( 16h 36m 56.7s , +30d 2m 05.3s) | C | 180 | 15.96 | 183471 | MASTER-Tavrida | ( 16h 37m 29.4s , +28d 1m 05.2s) | C | 180 | 17.40 | 183796 | MASTER-Tavrida | ( 16h 54m 05.2s , +28d 1m 33.1s) | C | 180 | 15.62 | 184166 | MASTER-Tavrida | ( 16h 54m 04.2s , +28d 1m 34.2s) | C | 180 | 14.77 | 185956 | MASTER-Tavrida | ( 16h 36m 38.0s , +28d 0m 20.0s) | C | 60 | 0.00 | 185956 | MASTER-Tavrida | ( 16h 36m 38.0s , +28d 0m 19.0s) | C | 60 | 0.00 | 186639 | MASTER-Tavrida | ( 16h 36m 38.0s , +28d 0m 19.0s) | C | 1 | 0.00 | 186658 | MASTER-Tavrida | ( 16h 36m 38.0s , +28d 0m 20.0s) | C | 1 | 0.00 | 173387 | MASTER-Amur | ( 16h 51m 30.0s , +29d 59m 58.0s) | C | 180 | 0.00 | 173503 | MASTER-Amur | ( 16h 53m 37.6s , +32d 0m 53.8s) | C | 180 | 12.00 | 173896 | MASTER-Amur | ( 16h 48m 07.0s , +31d 56m 51.0s) | C | 180 | 0.00 | 174290 | MASTER-Amur | ( 16h 48m 07.1s , +31d 56m 28.8s) | C | 180 | 0.00 | 174684 | MASTER-Amur | ( 16h 43m 10.8s , +35d 59m 26.3s) | C | 180 | 0.00 | 199897 | MASTER-Kislovodsk | ( 17h 20m 51.1s , +37d 57m 46.8s) | C | 180 | 17.41 | 200214 | MASTER-Kislovodsk | ( 17h 0m 33.4s , +37d 57m 07.1s) | C | 180 | 17.26 | 200214 | MASTER-Kislovodsk | ( 16h 49m 56.2s , +38d 23m 24.2s) | C | 180 | 17.50 | 200849 | MASTER-Kislovodsk | ( 16h 35m 57.7s , +41d 56m 29.3s) | C | 180 | 17.78 | 200849 | MASTER-Kislovodsk | ( 16h 24m 43.4s , +42d 22m 39.6s) | C | 180 | 17.95 | 201168 | MASTER-Kislovodsk | ( 17h 10m 11.5s , +38d 23m 39.1s) | C | 180 | 18.16 | 202754 | MASTER-Kislovodsk | ( 16h 35m 59.1s , +41d 55m 27.8s) | C | 180 | 17.86 | 202754 | MASTER-Kislovodsk | ( 16h 24m 44.9s , +42d 21m 35.6s) | C | 180 | 17.85 | 210692 | MASTER-Tavrida | ( 17h 12m 22.4s , +30d 0m 49.3s) | C | 180 | 17.88 | 211672 | MASTER-Tavrida | ( 17h 17m 00.5s , +32d 0m 48.3s) | C | 180 | 15.03 | 211672 | MASTER-Tavrida | ( 17h 15m 26.9s , +32d 0m 44.6s) | C | 180 | 17.93 | 212420 | MASTER-Kislovodsk | ( 17h 33m 19.7s , +35d 53m 45.1s) | C | 180 | 17.40 | 212420 | MASTER-Kislovodsk | ( 17h 23m 11.7s , +36d 20m 32.2s) | C | 180 | 17.46 | 212739 | MASTER-Kislovodsk | ( 16h 47m 56.1s , +39d 52m 17.4s) | C | 180 | 17.14 | 212739 | MASTER-Kislovodsk | ( 16h 37m 17.0s , +40d 19m 04.3s) | C | 180 | 17.37 | 212979 | MASTER-Tavrida | ( 17h 12m 23.4s , +30d 0m 42.0s) | C | 180 | 17.64 | 213303 | MASTER-Tavrida | ( 17h 12m 21.8s , +30d 0m 41.3s) | C | 180 | 17.70 | 213375 | MASTER-Kislovodsk | ( 17h 3m 26.6s , +36d 19m 54.0s) | C | 180 | 16.91 | 213375 | MASTER-Kislovodsk | ( 17h 13m 32.3s , +35d 53m 09.9s) | C | 180 | 16.92 | 213691 | MASTER-Kislovodsk | ( 17h 13m 32.3s , +35d 52m 44.3s) | C | 180 | 16.92 | 213691 | MASTER-Kislovodsk | ( 17h 3m 26.9s , +36d 19m 27.2s) | C | 180 | 16.91 | 213956 | MASTER-Tavrida | ( 17h 15m 26.3s , +32d 0m 16.7s) | C | 180 | 17.70 | 214009 | MASTER-Kislovodsk | ( 17h 33m 20.5s , +35d 53m 13.6s) | C | 180 | 17.32 | 214009 | MASTER-Kislovodsk | ( 17h 23m 13.7s , +36d 19m 57.2s) | C | 180 | 17.26 | 214326 | MASTER-Kislovodsk | ( 16h 47m 56.2s , +39d 52m 09.1s) | C | 180 | 17.05 | 214326 | MASTER-Kislovodsk | ( 16h 37m 18.0s , +40d 18m 51.6s) | C | 180 | 17.07 | 214644 | MASTER-Kislovodsk | ( 16h 37m 17.6s , +40d 18m 45.5s) | C | 180 | 17.13 | 215602 | MASTER-Tavrida | ( 17h 19m 55.1s , +34d 0m 32.8s) | C | 180 | 17.25 | 215926 | MASTER-Tavrida | ( 17h 19m 53.4s , +34d 0m 26.6s) | C | 180 | 17.30 | 217230 | MASTER-Tavrida | ( 17h 19m 53.5s , +34d 0m 14.0s) | C | 180 | 17.19 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The covered map is available http://master.sai.msu.ru/static//IPN/db/GRB181121.4/img/ligo_master_2018-11-26-05-01-55.eb.180.1.png Follow up observations are required.