GCN Circular 23113
Subject
GRB180809B: MASTER Triple Independent Automatic OT Detection
Date
2018-08-10T09:07:16Z (6 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
N.Tiurina, V. Lipunov, E. Gorbovskoy,
V.Kornilov, A.Kuznetsov, V.Chazov, I. Gorbunov,
D.Zimnukhov, D.Kuvshinov, P.Balanutsa, V.Vladimirov, D. Vlasenko
Lomonosov Moscow State University,SAI
R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres
The Instituto de Astrofisica de Canarias (IAC)
D. Buckley,
South African Astronomical Observatory (SAAO)
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)
We have already reported the observation of the optical transient GRB
180809B (Moss et al., GCN # 23105) by one of the telescopes of the MASTER
Global Network (Lipunov et al., GCN 23109).
Here we report on the triple independent, automatic detection of the
optical transient (also found by Swift UVOT (Moss et al., GCN 23105)). The
relatively later guidance of the three MASTER robotic telescopes is due to
the fact that the first socket message did not indicate the time of the
trigger. As a result, everyone went to the CALET Alert (trig
number 1217881726) with poor defined coordinates.
Nevertheless, we were able to obtain detailed light curves
with a maximum in 4 polarizations.
MASTER-SAAO robotic telescope (MASTER-Net: http://observ.pereplet.ru,
Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in
South Africa (South African Astronomical Observatory) was pointed to the
GRB180809.85 16 sec after notice time and 111 sec after trigger time at
2018-08-09 20:30:39 UT. On our 1-th (10s exposure) set in two
polarizations (/\), obtained 111
sec after tigger time at 2018-08-09 20:30:39 UT, we found 1 optical transient
within SWIFT error-box (ra=299.7 dec=-15.2989 r=0.05) brighter then 17.4.
T-Tmid Date Time Expt. Ra Dec Mag
s UT s
-------|--------------------|-------|-----------------|---------------|-------
116 2018-08-09 20:30:39 10 (19h 58m 48.0s , -15d 17m 57.1s) 16.5
The 5-sigma upper limit has been about 17.9 mag
The observations started on zenit distance = 21 deg., galactic latitude b
= -22 deg. The moon ( 4 % bright part) was below the horizon (The altitude
of the Moon = -75 deg ). The sun altitude = -56.3 degree. The object
can be observed till 2018-08-10 04:03:58 UT.
MASTER-Tavrida robotic telescope (MASTER-Net: http://observ.pereplet.ru,
Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in
Russia (Lomonosov MSU, SAI Crimea astronomical station) was pointed to the
GRB180809.85 35 sec after notice time and 133 sec after trigger time at
2018-08-09 20:31:01 UT. On our first (10s
exposure) set we found 1 optical transient within SWIFT error-box
(ra=299.7 dec=-15.2989 r=0.05) brighter then 17.9:
T-Tmid Date Time Expt. Ra Dec Mag
s UT s
------|--------------------|-------|-----------------|-----------------|-------
138 2018-08-09 20:31:01 10 ( 19h 58m 48.0s , -15d 17m 56.5s) 16.8
The 5-sigma upper limit has been about 17.9 mag
The observations made on zenit distance = 60 degrees, galaxy latitude b = -22 degree.
The moon ( 4 % bright part) below the horizon (The altitude of the Moon is
-25 degree ). The sun altitude is -27.0 degree.
The object can be observed till 2018-08-10 01:29:20.
MASTER-IAC robotic telescope (MASTER-Net: http://observ.pereplet.ru,
Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in
Spain (IAC Teide Observatory) was pointed to the GRB180809.85 120 sec
after notice time and 147 sec after trigger time at 2018-08-09 20:31:15
UT in two polarizations (|-).
On our first set, obtained we found 1 optical transient within SWIFT
error-box (ra=299.7 dec=-15.2989 r=0.05):
T-Tmid Date Time Expt. Ra Dec Mag
---------|---------------------|-------|-----------------|-----------------|-------
152 2018-08-10 20 31 15 20 ( 19h 58m 43.3s , -15d 20m 37.9s) 15.5
The 5-sigma upper limit has been about 16.0 magThe message may be cited.
The observations made on zenit distance = 44 degrees, galaxy latitude b =
-22 degree. The moon ( 3 % bright part) below the horizon (The altitude of
the Moon is -41 degree ). The sun altitude is -9.1 deg.
The object can be observed till 2018-08-10 05:19:05 UT.
The message may be cited.