GCN Circular 19748

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
Not found
 
 
)  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
Not found
 
 
) 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.