TITLE: GCN CIRCULAR NUMBER: 19748 SUBJECT: Global MASTER net follow up of IceCube-160731A DATE: 16/08/01 16:44:51 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, E.S. Gorbovskoy, N.Tyurina, V.Kornilov, P.Balanutsa, A.Kuznetsov, D.Kuvshinov, I.Gorbunov Lomonosov Moscow State University, Sternberg Astronomical Institute A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov Kislovodsk Solar Station of the Pulkovo Observatory D.Buckley, S. Potter, A.Kniazev, M.Kotze South African Astronomical Observatory R.Rebolo, M.Serra, N.Lodieu, G.Israelian The Instituto de Astrofisica de Canarias R.Podesta, C.Lopez and F.Podest Observatorio Astronomico Felix Aguilar (OAFA), San Juan National University H.Levato and C.Saffe Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE) O.Gres, K.Ivanov, S.Yazev, N.M.Budnev, O.Chuvalaev, V.A.Poleshchuk Irkutsk State University V.Yurkov, Yu.Sergienko, A.Gabovich, E.Sinyakov Blagoveschensk Educational State University, Blagoveschensk MASTER Global robotic Net (MASTER-Net: http://observ.pereplet.ru) received IceCube HESE event IceCube-160731A (AMON ICECUBE HESE 128290 6888376) at 2016-07-31 01:55:34.5 UT (30s after the EHE_event_time). At the alert time there was a day at MASTER-Amur, -Tunka, -Kislovodsk. It was under the horizont at At MASTER-SAAO ( -42.52deg ) and MASTER-IAC ( -14.50). MASTER-OAFA (Argentina) did not received alert due to problems with internet. So we started observations at the following night. MASTER-Kislovodsk robotic telescope (Kislovodsk, Russia) was pointed to the IceCube neutrino 160731 event (Taboada et al GCN 19743) 61241 sec after trigger time at 2016-07-31 19:23:17 UT. The 5-sigma upper limit has been about 19.0 on single (180 sec) and 19.8 on coadd (1260 sec ) unfiletered images. MASTER-IAC robotic telescope (Teide observatory, Canary Islands/Spain) was pointed to the IceCube neutrino 160731 event 68442 sec after trigger time at 2016-07-31 21:25:16 UT. The 5-sigma upper limit has been about 20.0 on single (180 sec) and 20.7 on coadd (2160 sec ) unfiletered images. MASTER-OAFA robotic telescope (Felix Aguilar observatory, Argentina) was pointed to the IceCube neutrino 160731 event 75655 sec after trigger time at 2016-07-31 22:55:29 UT. The 5-sigma upper limit has been about 19.8 on single (180 sec) and 20.5 on coadd (3600 sec ) unfiletered images. No astrophysical OT detected inseide 2 square degrees around center AMON ICECUBE HESE 128290 6888376 error-box. However we detected and found: 1. MASTER OT J142038.73-002500.1 - the one point-like partical CCD event from AMON ICECUBE HESE 128290 6888376 event error box. Date Time Expt. Ra Dec Mag |---------------------|-------|-----------------|-----------------|------- 2016-07-31 19:26:57 180 (14h 20m 38.73s -00d 25m 00.1s) 17.9 2. The very bright NGC5584 galaxy (12.8 mag) presented at Ice Cube error box. Totaly there is 19 Galaxy up to 17 mag at Ice Cube error box. The brightest galaxy at error box highlighted at out most deep image: IAC images (lim = 20.7) is available at http://master.sai.msu.ru/static/IceCube160731.png OAFA image (lim= 20.4) is available at http://master.sai.msu.ru/static/IceCube160731a.png 3. We checked Swift X-ray sources (Evans et al., GCN 19747) inside this IceCube error-box. The Source1 (215.69403d, -0.63777d) is a bright known star HD 125981 (A3IV, Skiff, Catalogue of Stellar Spectral Classifications), MASTER doesnt' see variability. The Source2 (214.90209d, -0.14592d) : there is no OT in MASTER-Net database up to 20.7 unfiltered optical limit. There is infrared source (AllWise, etc) in 2.2". The Source3 (215.72267, -0.03074): there is a source with m_OT=19.0 without changhing with respect to MASTER-Net database. There is a USNO-B1 star with B2=19.49, R2=18.93.This star is a GALEX source (possible accretion to the white dwarf companion). The Source4 (215.72267, -0.60004): there is no source in MASTER images (20.7 unfiltered optical limit in 68442sec after trigger) and in VIZIER database (22m optical limit from POSS images). The Source 5(214.95898, -0.11266) . There is a Sloan QSO in 4.1" , no change with respect to MASTER database. The Source 6 (214.61169, 0.24144). Known bright star (USNO-B1 B2=15.30, R2=13.77,I=12.36), also a Galex source, i.e. possible accretting white dwarf) without variability on MASTER database. Results: Source 1, 3, 6 not coonected with IceCube event. Swift XRT sources 2,4,5 are interested. The message may be cited.