|
Description
We report the analysis of the microlensing event OGLE-2018-BLG-0677. A small feature in the light curve of the event leads to the discovery that the lens is a star-planet system. Although there are two degenerate solutions that could not be distinguished for this event, both lead to a similar planet-host mass ratio. We perform a Bayesian analysis based on a Galactic model to obtain the properties of the system and find that the planet corresponds to a super- Earth/sub-Neptune with a mass of M_planet_=3.96_-2.66_^+5.88^M_{Earth}_. The host star has a mass of M_host_=0.12_-0.08_^+0.14^M_{odot}_. The projected separation for the inner and outer solutions are 0.63_-0.17_^+0.20^au and 0.72_-0.19_^+0.23^au respectively. At {Delta}{chi}^2^={chi}^2^(1L1S-{chi}^2^(2L1S)=46, this is by far the lowest {Delta}{chi}^2^ for any securely detected microlensing planet to date, a feature that is closely connected to the fact that it is detected primarily via a "dip" rather than a "bump."
|
