[vsnet-grb-info 23768] GRB 190928A: MASTER optical observations

Mon Sep 30 19:34:59 JST 2019

TITLE:   GCN CIRCULAR
NUMBER:  25867
SUBJECT: GRB 190928A: MASTER optical observations
DATE:    19/09/30 10:33:55 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov at xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tiurina, F.Balakin, P.Balanutsa,A.Kuznetsov, V.Vladimirov, D. Vlasenko, I.Gorbunov,
D.Zimnukhov,V.Senik, T.Pogrosheva, K.Pozdnyakov, A.Chasovnikov, V.Topolev, D.Kuvshinov(Lomonosov Moscow State University, SAI, Physics Department),
R. Podesta, C.Lopez, F. Podesta, C.Francile(Observatorio Astronomico Felix Aguilar OAFA),
H.Levato(Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE),
R. Rebolo, M. Serra(The Instituto de Astrofisica de Canarias),
D. Buckley(South African Astronomical Observatory),
O.A. Gres, N.M. Budnev, O.Ershova(Irkutsk State University, API),
A. Tlatov, D. Dormidontov(Kislovodsk Solar Station of the Pulkovo Observatory),
V. Yurkov, A. Gabovich, Yu. Sergienko(Blagoveschensk Educational State University)

MASTER Global Robotic Net (http://observ.pereplet.ru, Lipunov et al., 2010,Advances in Astronomy, vol.2010, 30L)
started inspect of long/bright (Hurley et al. IPN triangulation GCN 25864)
GRB 190928A (Ursi  et al. AGILE GCN 25859 , GCN 25865)

MASTER-SAAO robotic telescope located in South Africa (South African Astronomical Observatory)
  started inspect of the IPN GRB190928.55/GRB190928A errorbox  43353 sec after trigger time at 2019-09-29 01:14:49 UT,
with upper limit up to  19.8 mag.
The observations began at zenit distance = 54 deg. The sun  altitude is -38.1 deg.

MASTER-IAC robotic telescope  located in Spain (IAC Teide Observatory) 
started inspect of the IPN GRB190928.55 errorbox  50163 sec after trigger time at 2019-09-29 03:08:19 UT,
with upper limit up to  20.1 mag.
  The observations began at zenit distance =  4 deg. The sun  altitude  is -48.7 deg.

MASTER-Amur robotic telescope  located in Russia (Blagoveshchensk State Pedagogical University)
started inspect of the IPN GRB190928.55 errorbox  77575 sec after trigger time at 2019-09-29 10:45:11 UT,
with upper limit up to  17.2 mag.
Observations started at twilight.  The observations began at zenit distance = 67 deg. The sun  altitude  was -15.1 deg.

MASTER-Tunka robotic telescope  located in Russia (Applied Physics Institute, Irkutsk State University)
started inspect of the IPN GRB190928.55 errorbox  83489 sec after trigger time at 2019-09-29 12:23:45UT,
with upper limit up to  20.0 mag. Observations started at twilight. 
The observations began at zenit distance = 67 deg. The sun  altitude  is -15.2 deg.

MASTER-Kislovodsk robotic telescope  located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory)
started inspect of the IPN GRB190928.55 errorbox  1 days 18913 sec after trigger time at 2019-09-29 18:27:29 UT,
with upper limit up to  20.4 mag.
The observations began at zenit distance = 63 deg. The sun  altitude  is -36.9 deg.

The error-box center galactic latitude b = -60 deg., longitude l = 98 deg.

We obtained following upper limits.

Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________
    43444 | 2019-09-29 01:14:49 |         MASTER-SAAO | (02h 47m 41.951s , +22d 01m 46.67s) |   C |   180 | 17.2 |
    43662 | 2019-09-29 01:18:27 |         MASTER-SAAO | (02h 32m 39.043s , +24d 01m 24.20s) |   C |   180 | 14.7 |
    50253 | 2019-09-29 03:08:19 |          MASTER-IAC | (02h 31m 38.751s , +23d 59m 41.60s) |   C |   180 | 19.9 |
    50254 | 2019-09-29 03:08:19 |          MASTER-IAC | (02h 40m 38.749s , +23d 55m 43.19s) |   C |   180 | 20.1 |
    51547 | 2019-09-29 03:29:52 |          MASTER-IAC | (02h 31m 36.457s , +23d 59m 19.80s) |   C |   180 | 19.9 |
    51547 | 2019-09-29 03:29:52 |          MASTER-IAC | (02h 40m 36.860s , +23d 55m 26.72s) |   C |   180 | 20.1 |
    51803 | 2019-09-29 03:34:09 |          MASTER-IAC | (02h 38m 14.592s , +21d 54m 59.78s) |   C |   180 | 20.0 |
    52057 | 2019-09-29 03:38:22 |          MASTER-IAC | (02h 46m 38.495s , +21d 59m 15.57s) |   C |   180 | 20.0 |

MASTER real time updated cover map of GRB190928A  and our upper limits are available at
https://master.sai.msu.ru/site/master2/ligo_1.php?id=10845

MASTER OT J020953.61+360533.8 discovery

During inspect, MASTER-Kislovodsk auto-detection system discovered OT source at
(RA, Dec) = 02h 09m 53.61s +36d 05m 33.8s on 2019-09-29.86025UT.

The OT unfiltered magnitude is 18.4m (mlimit 19.9m).
The OT is seen in 2 images. There is no minor planet at this place.

We have reference images without OT on 2014-10-28.91229 UT with unfiltered 
magnitude limit 20.6m, nearest in time on 2019-06-19 23:25:49 with mlim=18.2 (MASTER-Kislovodsk).

Our preliminary classification is CV, but 
Spectral observations are required.

The discovery and reference images are available at:
http://master.sai.msu.ru/static/OT/020953.61360533.8.png