[vsnet-grb-info 22380] LIGO/Virgo S190510g : Xinglong-60cm upper limit of the GRAWITA REM s OT

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  24479
SUBJECT: LIGO/Virgo S190510g : Xinglong-60cm upper limit of the GRAWITA REM's OT
DATE:    19/05/11 10:40:06 GMT
FROM:    Dong Xu at NAOC/CAS  <dxu at nao.cas.cn>

Z.P. Zhu, D. Xu, B.Y. Yu, J.J. Ren, T.M. Zhang, X. Zhou, H.J. Wang, C.Z. 
Cui, D.W. Fan, Y.F. Xu (NAOC), X. Gao (Urumqi No.1 Senior High School), 
S. Yang (INAF-OAPd), H.B. Zhao, B. Li (PMO), J.Z. Liu, H.B. Niu (XAO), 
J.R. Mao, J.M. Bai (YNAO), report on behalf of the GWFUNC collaboration:

We observed the optical transient (OT), r = 17.3 +/- 0.1 (AB, calibrated 
against
the SDSS), in P. D'Avanzo et al. (GCN 24455) of the gravitational-wave 
event S190510g (GCN 24442) using the Xinglong-60cm telescope located at 
Xinglong, Hebei, China.

The OT is ~20" away from the SDSS galaxy, SDSS J142914.95+094059.4, 
which has a photoZ=0.041 +/- 0.0149, corresponding to a luminosity 
distance of 182.2 Mpc, thus being consistent with the LIGO's luminosity 
distance estimate of 227 +/- 92 Mpc (GCN 24448). At the above redshift, 
SDSS J142914.95+094059.4 has an absolute magnitude of M(r) = 17.92-36.30 
= -18.38, at the border of dwarf/normal galaxies. The OT is ~16.3 kpc 
away from the nucleus of the SDSS galaxy, much larger than usual radii 
of such galaxies. If double neutron stars are considered having been 
kicked out of their host galaxy earlier before, such a scenario might be 
possible.

Under the above assumption, we obtained 15x360 s frames in R band, 
started at 16:12:27 on 2019-05-10, i.e., about 10 hr after the OT 
detected. The OT has decayed and is not detected in our stacked image of 
5400 s, down to a limiting magnitude of r ~ 20.6, calibrated with the 
SDSS field.