[vsnet-grb-info 20103] GRB 171205A: MASTER-SAAO optical observations of unusual OT

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  22199
SUBJECT: GRB 171205A: MASTER-SAAO optical observations of unusual OT 
DATE:    17/12/07 16:35:25 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov at xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, D.Kuvshinov, A.V.Krylov,
I.Gorbunov, P.Balanutsa, A.Kuznetsov, V.V.Chazov, D. Vlasenko
Lomonosov Moscow State University, Sternberg Astronomical Institut of MSU

D.Buckley, S. Potter, A.Kniazev, M.Kotze
South African Astronomical Observatory

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

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

H. Levato, C. Saffe
Instituto de Ciencias Astronomicas,de la Tierra y del Espacio (ICATE),
San Juan, Argentina

O.Gres, K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk,
Irkutsk State University

V.Yurkov, Yu.Sergienko
Blagoveschensk Educational State University, Blagoveschensk

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

MASTER-SAAO telescope observed Swift GRB171205A (D'Elia et al., GCN Circ. 
22177) since 2017-12-06 23:53:47UT.

There were 20 images with 180s exposition in B and unfiltered (W=0.2B+0.8R 
calibrated by USNO-B1) .

MASTER-SAAO auto-detection system detected optical transient ((Izzo et 
al. GCN 22180; Emery et al. GCN 22181; Butler et al. GCN 22182; Mao et al. 
GCN 22186; Choi et al. GCN 22188; Melandri et al. GCN 22189; Steeghs et 
al. GCN 22190; Cobb et al. GCN 22192, Schmidl et al. GCN22198) several 
filters. The unfriltered magnitude is about ~ 19.4 mag .

We note that absolute magnitude is about -16.5.

The dicovery image is available at 
http://observ.pereplet.ru/images/MASTERGRB171205A.jpg


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