S. J. Smartt, K. W. Smith, D. R. Young, O. McBrien, J. Gillanders. S. Srivastav,
D. O���Neil, P. Clark, S. Sim (QUB), L. Denneau, H. Flewelling, A. Heinze,
J. Tonry, H. Weiland K. C. Chambers , M. Huber, E. Magnier,
A. Schultz, (IfA, Univ. Hawaii), A. Rest (STScI), B. Stalder (LSST),
C. Stubbs (Harvard)
Lipunov et al (GCN 24076) reported the discovery of an optical transient
MASTER OT J140518.22-395309.9 close to the southern part of the
skymap of LIGO/Virgo source S190408an.
The ATLAS survey (Tonry et al. 2018, Stalder et al. 2016) has detected
this source since MJD=58555 (2019-03-13) at o = 17.4. It peaked around
MJD=58569 at o = 17 and has a SN like lightcurve. There is no obvious
catalogued host galaxy.
In summary, we confirm the discovery of MASTER that this is a real
optical transient (with no host galaxy) at coordinates :
But that it is almost certainly a foreground SN about 1 month old,
and very unlikely to be related to LIGO/Virgo S190408an.