TITLE:   GCN CIRCULAR
NUMBER:  33861
SUBJECT: LIGO/Virgo/KAGRA S230521k: MASTER new OT discovery
DATE:    23/05/24 00:18:42 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>

V.Lipunov, Ya.Kechin (Lomonosov MSU), D.Buckley (SAAO),
K.Zhirkov, A.Kuznetsov, P.Balanutsa, A.Chasovnikov, O.Gress, N.Tiurina,E.Gorbovskoy, G.Antipov, D.Vlasenko,  V.Senik,
V.Topolev, Yu.Tselik, Siyu Wu, V.Vladimirov, D.Cheryasov, D.Zimnukhov, T.Pogrosheva, V.Shumkov, K.Vetrov (Lomonosov Moscow State University, SAI,Physics Department),
C.Francile, F. Podesta, C.Lopez, R. Podesta (Observatorio Astronomico Felix Aguilar OAFA),
R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias),
L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez,A.Corella,L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory),
N.M.Budnev, O.Ershova (ISU,API),
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),
A. Gabovich, V.Yurkov (Blagoveschensk Educational State University),
M.Gulyaev, E.Minkina (Lomonosov MSU)


MASTER OT J071612.28-415537.5 discovery

During LVC S230521k https://gcn.gsfc.nasa.gov/notices_l/S230521k.lvc
inspection survey (Lipunov et al. GCN 33849)
MASTER-SAAO auto-detection system ( Lipunov et al., "MASTER Global Robotic Net", Advances in Astronomy, 2010, 30L )
 discovered OT source at (R.A.,Dec.2000) = 07h 16m 12.28s -41d 55m 37.5s on 2023-05-23.71558 UT.

The OT unfiltered magnitude is 18.2m (mlim=19.0).

The OT is seen in 4 images. There is no minor planet at this place.

We have reference images on 2021-02-16 02:18:16UT with mlim=19.5,
on 2014-12-24.97843 UT with  unfiltered mlim=19.7m and other, there is no outbursts at automatic light curve, but analysis of archive images will be continued.

Spectral observations and deep photometry are required.
Observations and analysis will be continued.