[vsnet-grb-info 20844] IceCube-170922A: First Optical observations of the Neutrino Trigger by MASTER Global Net and 25 IceCube alerts inspection.

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  22942
SUBJECT: IceCube-170922A: First Optical observations of the  Neutrino Trigger by  MASTER Global Net  and 25 IceCube alerts inspection.
DATE:    18/07/12 16:51:56 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov at xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, V.Kornilov,  N.Tiurina, A.Kuznetsov, V.Chazov,
I. Gorbunov, D. Vlasenko, D.Zimnukhov, D.Kuvshinov, P.Balanutsa, V.Vladimirov
Lomonosov Moscow State University,SAI

D. Buckley,
South African Astronomical Observatory (SAAO)

R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres
The Instituto de Astrofisica de Canarias (IAC)

A. Tlatov, V.Senik, D. Dormidontov
Kislovodsk Solar Station of the Pulkovo Observatory

R. Podesta, F. Podesta, C. Lopez, C.Francile
Observatorio Astronomico Felix Aguilar (OAFA)

H.Levato,
Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE)

O. Gres, N.M.Budnev , Yu.Ishmuhametova
Irkutsk State University (ISU)

A. Gabovich, V. Yurkov, Yu. Sergienko
Blagoveschensk Educational State University, Blagoveschensk

MASTER-Tavrida  robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in Crimea was pointed to the   IceCube-170922A (Kopper  et al. 
GCN #21916; ) 27 sec after notice 
time and 73 sec after trigger time at 2017-09-22 20:55:43 UT. On our first 
(180s exposure)  set we cleary detected TXS 0506+056   within ICECUBE 
error-box (ra=77.2833 dec=5.75139 r=0.25).
The 5-sigma upper limit has been about 17.5 mag on single and 19.5  on 
coadd images.

Since 2017-09-22 20:55:43 (i.e 73 sec after trigger) till 2017-09-18 we 
have ~ 300 observations provided by MASTER-Tavrida, MASTER-SAAO, 
MASTER-OAFA, MASTER-Kislovodsk and MASTER-Blagoveschensk.

The object zenith distance was 84 degree at a time of first observations 
and it was rise.

Unfortunately, we were extremely busy at this time handling the kiln on 
August 17, 2017, which we detected independent of the Chilean 
telescopes (Abbot et al 2017ApJ...848L..12A; Lipunov et al. 
2017ApJ...850L...1L).

Our telescopes react to 25 IceCube neutrino alerts ( 5874 images!), 
starting with the famous 
neutrino triplet in whose publication we participate and made a decisive 
contribution to the optical inspection (Aartsen et al 2017, A&A, Vol 607, 
A115, DOI: 10.1051/0004-6361/201730620)

Just in case, we report that we have previous, synchronous and subsequent 
optical observations of the ICECube neutrino alert on June  2018.

Just in case, we report that we have precursor and synchronous 
observations  of the   neutrino alert of June  2018 with QSO inside 2 sigma 
error box.

The message may be cited.