TITLE:   GCN CIRCULAR
NUMBER:  27077
SUBJECT: LIGO/Virgo S200213t:  MASTER possible Kilonova candidate in PGC315337
DATE:    20/02/15 14:47:28 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov,  V.Shumkov, E. Gorbovskoy, V.Kornilov, P.Balanutsa, N.Tyurina, V.Vladimirov, A.Kuznetsov,
F.Balakin, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
A.Chasovnikov, D.Kuvshinov (Lomonosov Moscow State University, SAI, Physics Department),
O.A. Gres, N.M. Budnev, O.Ershova (Irkutsk State University, API),
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),
V. Yurkov, A. Gabovich, Yu. Sergienko(Blagoveschensk Educational State University)
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),

MASTER Global Robotic Net (http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)
covered 1525 square degrees of S299213t (LVC GCN 27042, Lipunov et al. GCN 27041, GCN 27072
https://gcn.gsfc.nasa.gov/other/S200213t.gcn3 )
that is equal to 100% of 50%-error-field and 81% of 90%-error-field
https://master.sai.msu.ru/site/master2/ligo_1.php?id=11331

MASTER OT J044008.76-651302.3 discovery - OT in 15"W,39.5"S from PGC315337 center (in 3-sigma of LVC error-box)
AT2020cph

MASTER-SAAO auto-detection system  discovered OT source at
R.A.,Dec(2000) = 04h 40m 08.76s -65d 13m 02.3s on 2020-02-14.91294 UT.

The OT unfiltered magnitude (automatic photometry):
2020-02-13 22:03:33UT     19.6
2020-02-14 02:11:16UT     19.0
2020-02-14 22:04:43UT     18.9

We have reference image on 2017-12-22.95279 UT with  unfiltered mlim= 20.3m, nearest in time at
2020-01-27 20:13:33 with mlim=19.0

Spectral observations are required.

PGC315337 has Btc=16.2 (no V in LEDA)

Observations and  analysys will be continued.
The message may be cited.