[vsnet-grb-info 22034] Fermi trigger 576241792 / GRB 190406B: MASTER optical observation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  24133
SUBJECT: Fermi trigger 576241792 / GRB 190406B: MASTER optical observation 
DATE:    19/04/19 17:30:29 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov at xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, N.Tyurina, V.Kornilov, D.Vlasenko, V.Vladimirov, D.Zimnukhov,
A.Kuznetsov, P.Balanutsa, A. Chasovnikov, V.Topolev, D.Kuvshinov, F.Balakin (Lomonosov Moscow State University, SAI, Physics Department),

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

D. Buckley (South African Astronomical Observatory),

O. Gress, N.M. Budnev, O.Ershova (Applied Physics Institute, Irkutsk State University),

V. Yurkov, A. Gabovich, Yu. Sergienko, D. Kobcev (Blagoveschensk Educational State University),


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

R. Podesta, C. Lopez, C.Francile, F. Podesta (Observatorio Astronomico Felix Aguilar OAFA, San Juan National University),

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

MASTER Global Robotic Net (http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, v. 2010, 30L)
automatically started inspection of  Fermi trigger 576241792 https://gcn.gsfc.nasa.gov/other/576241792.fermi
7843s after trigger time at 2019-04-06  13:20:30 UT

MASTER Net cover map is available at http://observ.pereplet.ru/images/MASTER_FermiTrig576241792covermap.jpg

MASTER-Tunka robotic telescope located in Russia (Applied Physics Institute, Irkutsk State University)
was pointed to the  FERMI GRB190406.47 ( 19h  5m 21.60s , +61d 30m 00.00s, R=7.09)
7843 sec after trigger time at 2019-04-06 13:20:30 UT, with upper limit up to  19.8 mag.
Observations started at twilight.  The observations began at zenit distance = 65 deg. The sun  altitude  is -14.6 deg.

MASTER-Kislovodsk robotic telescope  located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory)
started FERMI GRB190406.47 / trigger 576241792 inspection  20777 sec after trigger time at 2019-04-06 16:56:04 UT, 
with upper limit up to  19.9 mag. Observations started at twilight.
  The observations began at zenit distance = 74 deg. The sun  altitude  is -13.8 deg.

MASTER-Tavrida robotic telescope  located in Russia (Lomonosov MSU, SAI Crimea astronomical station)
started FERMI GRB190406.47 inspection 26157 sec after trigger time at 2019-04-06 18:25:44 UT, with upper limit up to  19.5 mag.
The observations began at zenit distance = 70 deg. The sun  altitude  is -22.5 deg.

MASTER-IAC robotic telescope  located in Spain (IAC Teide Observatory) started
  FERMI GRB190406.47 inspection 39426 sec after trigger time at 2019-04-06 22:06:53 UT, with upper limit up to  20.1 mag.
The observations began at zenit distance = 84 deg. The sun  altitude  is -34.8 deg.

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


MASTER auto-detection system didn't find OT connected with GRB.

During inspection we find OT

MASTER OT J193011.47+465928.3 detection - preliminary dwarf nova outburst, ampl>4.3m

MASTER-Kislovodsk auto-detection system (Lipunov et al., 2010, Advances in Astronomy, v. 2010, 30L)
discovered OT source at (RA, Dec) = 19h 30m 11.47s +46d 59m 28.3s on 2019-04-07.95397 UT.
The OT unfiltered magnitude is 15.4m (limit 19.0m).

The OT is seen in 8 images. There is no minor planet at this place.

We have reference image without OT on 2019-02-13.08602 UT with unfiltered 
magnitude limit 19.6m, on 2016-07-29 21:12:44 with mlim=19.7, it means 
more then 4.3m of current outburst amplitude (there is USNO-B1 star in 0.3" with B1=19.5,R2=19.3).

Spectral observations are required.

The discovery and reference images are available at:
http://master.sai.msu.ru/static/OT/193011.47465928.3.png

We checked coordinates of 4 ZTF candidates (Ahumada et al. GCN24130) in 
MASTER database  and didn't find OT at position of 3 ones since 2009y (up to unfiltered 20.0)

About ZTF19aapfxqv
MASTER has seen an object at the position 
18h 27m 39.96s , +65d 37m 33.70s (MASTER OT J182739.96+653733.70) 
on 2017-12-07 21:15:28.334UT with m_OT=18.3+-0.2 (and we should note there 
is PanSTARRs source in 5.7").

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