[vsnet-grb-info 21045] GRB 180728A: MASTER early polarization and 19 days monitoring

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  23143
SUBJECT: GRB 180728A: MASTER early polarization and 19 days monitoring 
DATE:    18/08/16 20:33:39 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov at xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, N.Tiurina, D.Vlasenko, V.Kornilov, A.Kuznetsov,
V.Chazov, I.  Gorbunov, 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 (BSPU)

MASTER Global Robotic Net ( Lipunov et al., 2010, Advances in Astronomy, 
vol. 2010, 30L) inspected GRB 180728A
(SwiftBAT GRB discovery : Starling et al. GCN 23046;
MASTER optical counterpart discovery: Lipunov et al. GCN 23048;GCN23050;
SwiftXRT: Perri et al. GCN 23049; Redshift, VLT: Rossi et al. GCN 23055;
SN discovery,VLT: Izzo et al. GCN 23142).
every night since the discovery.

There are unfiltered limits at MASTER images and absolute magnitude of 
SN ( Izzo et al. GCN 23142) for
Omega_Vac = 0.7 and H_0 = 70 km/s/Mpc and Galactic extinction 0.1 for our 
red ccd:

Date_Time,UT            |   Exp,s | MASTER-Site |  m_lim| M

2018-07-29 21:18:37.092 |    2340 | MASTER-SAAO |  21.8 | -16.3
2018-07-30 21:07:24.839 |    1440 | MASTER-SAAO |  20.8 | -17.3
2018-07-30 21:07:24.912 |    1440 | MASTER-SAAO |  21.4 | -16.7
2018-08-01 19:11:32.906 |    1620 | MASTER-SAAO |  20.9 | -17.2
2018-08-01 19:15:07.977 |    1620 | MASTER-SAAO |  20.9 | -17.2
2018-08-02 17:03:40.025 |    3780 | MASTER-SAAO |  20.8 | -17.2
2018-08-02 18:12:49.446 |    3960 | MASTER-SAAO |  20.9 | -17.2
2018-08-03 17:53:21.097 |    4140 | MASTER-SAAO |  20.8 | -17.3
2018-08-03 17:53:21.347 |    4140 | MASTER-SAAO |  21.1 | -17.0
2018-08-03 23:21:10.842 |    3420 | MASTER-OAFA |  20.6 | -17.5
2018-08-04 17:05:35.120 |    2700 | MASTER-SAAO |  20.9 | -17.2
2018-08-04 17:12:46.879 |    2880 | MASTER-SAAO |  20.8 | -17.3
2018-08-04 23:07:09.154 |     720 | MASTER-OAFA |  20.5 | -17.6
2018-08-05 22:18:29.225 |    3240 | MASTER-SAAO |  20.8 | -17.3
2018-08-05 22:22:04.704 |    3240 | MASTER-SAAO |  21.1 | -17.0
2018-08-05 23:08:46.934 |    1260 | MASTER-OAFA |  21.5 | -16.5
2018-08-06 18:46:19.565 |    3600 | MASTER-SAAO |  20.8 | -17.3
2018-08-06 18:46:19.605 |    3600 | MASTER-SAAO |  20.8 | -17.3
2018-08-07 00:26:41.653 |     900 | MASTER-OAFA |  20.4 | -17.7
2018-08-07 03:30:36.096 |    2520 | MASTER-OAFA |  20.6 | -17.5
2018-08-07 17:15:34.447 |    3780 | MASTER-SAAO |  20.9 | -17.2
2018-08-07 18:23:07.857 |    3780 | MASTER-SAAO |  21.7 | -16.4
2018-08-08 17:59:05.042 |    4140 | MASTER-SAAO |  20.8 | -17.3
2018-08-08 18:02:42.597 |    4140 | MASTER-SAAO |  20.9 | -17.2
2018-08-08 23:11:34.904 |    3240 | MASTER-OAFA |  21.9 | -16.2
2018-08-09 18:55:17.807 |     540 | MASTER-SAAO |  20.8 | -17.2
2018-08-09 18:58:54.517 |     540 | MASTER-SAAO |  20.8 | -17.2
2018-08-09 23:04:26.723 |    3240 | MASTER-OAFA |  20.5 | -17.5
2018-08-10 17:00:41.943 |    2520 | MASTER-SAAO |  20.9 | -17.1
2018-08-11 00:08:05.570 |    4500 | MASTER-OAFA |  20.7 | -17.3
2018-08-11 18:43:29.720 |    7020 | MASTER-SAAO |  20.9 | -17.1
2018-08-11 23:12:32.140 |    3240 | MASTER-OAFA |  20.6 | -17.4
2018-08-12 19:46:57.192 |    7560 | MASTER-SAAO |  22.1 | -15.9
2018-08-12 19:46:57.246 |    7560 | MASTER-SAAO |  20.9 | -17.1
2018-08-12 23:18:02.053 |    3240 | MASTER-OAFA |  19.8 | -18.2
2018-08-13 07:43:55.504 |    3420 | MASTER-OAFA |  21.2 | -16.8

We have carried out preliminary photometry of MASTER early observations
  (Lipunov et al. GCN 23048; GCN23050;) also we report about 
considerable polarization of optical radiation of gamma burst the first 
minute after its beginning.

This message can be cited.