GCN Circular 25370

V. Lipunov, F.Balakin, E. Gorbovskoy, V. Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, V. Vladimirov,
D. Vlasenko, I.Gorbunov,D.Zimnukhov, V. Senik, A.Chasovnikov, A.Pozdnyakov,D.Kuvshinov(Lomonosov Moscow State University, SAI, Physics Department),
R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias IAC),
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),
D. Buckley (South African Astronomical Observatory SAAO),
O. Gress, 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)
observed S190814bv (LVC GCN 25324
Not found
 
 
) starting 2019-08-14 22:42:29 (Lipunov 
et al. GCN 25322
Not found
 
 
, GCN25339
Not found
 
 
).

We analyzed candidates identified in DECam images by the DECam-GROWTH team (Andreoni et al. GCN25362
Not found
 
 
)
in MASTER-Kislovodsk, MASTER-Tavrida, MASTER-SAAO,MASTER-IAC,MASTER-OAFA databases
and in VIZIER.

1) 11.736272 -25.376851
There is PanSTARRs optical source in 0.14" with m=20.2(r) and sources in the halo of NGC253 (Bailin+, 2011)
http://vizier.u-strasbg.fr/viz-bin/VizieR?-source=&-out.add=_r&-out.add=_RAJ%2C_DEJ&-sort=_r&-to=&-out.max=20&-meta.ucd=2&-meta.foot=1&-c=11.736272+-25.376851&-c.rs=5
MASTER observed this area since 2015-09-15 23:55:17(mlim=20.2),
there was no automatically detected sources brighter mlim in history,
and now mlim~18 (full Moon in 38deg., 30 deg. obj_altitude).

2) 10.388877 -23.742207
There is OT with unfiltered m=18.2 on 2018-08-10 01:07:54.917UT in MASTER database

3) 11.548253 -22.118828
There is no OT up to 21.4 (2018-11-02 23:59:06UT) in MASTER database, 
in VIZIER there is  WISE AGN candidate (catalogs Assef+, 2018) in 2.9"

4)14.050077 -25.490123
There is optical surce in MASTER images, for ex. (2015-09-15 23:55:17) with  unfiltered m~21 (mlim=21.5)

there are 2 PanSTARRs sources in 1.4 and 2.1"
http://vizier.u-strasbg.fr/viz-bin/VizieR?-source=&-out.add=_r&-out.add=_RAJ%2C_DEJ&-sort=_r&-to=&-out.max=20&-meta.ucd=2&-meta.foot=1&-c=14.050077+-25.490123&-c.rs=5

5)13.968328 -25.783281
There is marginally seen source with m<~mlim=20.0 on 2019-08-15 00:12:22
and m_OT~20.5 on 2015-09-15 23:55:17UT (mlim=21.5)
There is USNO-B1 source in 1.2" with R2=21.3, B2=21.0 and PanSTARRs source with r=21.2

6)13.273165 -24.360753
There is a source in our images.
MASTER automatic photometry is the following
Date_TimeUT           unfiltered_m
2019-05-12 03:17:15   19.2
2018-11-03 00:49:21   19.6
2015-01-11 19:31:53   19.2

7)22.265283 -32.705156
There is marginally seen optical source at 2015-09-10 01:36:50Ut (the best summ with mlim=20.8)
with m_OT~20.5 in MASTEr database.
Also in 2" in VIZIEr database there is a source in USNO-B1, PanSTARR(2.38"), GALEX (3")

The observation and reduction of LVC error-box will be continued.