MOA-2010-BLG-117 - Half-Jupiter-mass planet in system lensing two background stars

Admin Number of posts : 4320 Location : Earth Registration date : 2008-04-06

The First Planetary Microlensing Event with Two Microlensed Source Stars
https://arxiv.org/abs/1707.09667

Quote :: We present the analysis of microlensing event MOA-2010-BLG-117, and show that the light curve can only be explained by the gravitational lensing of a binary source star by a star with a Jupiter mass ratio planet. It was necessary to modify standard microlensing modeling methods to find the correct light curve solution for this binary-source, binary-lens event. We are able to measure a strong microlensing parallax signal, which yields the masses of the host star, M∗=0.58±0.10M⊙, and planet mp=0.51±0.07MJup at a projected star-planet separation of a⊥=2.44±0.26AU, corresponding to a semi-major axis of a=2.9+1.6−0.5AU. Thus, the system resembles a half-scale model of the Sun-Jupiter system with a half-Jupiter mass planet orbiting a half-solar mass star at very roughly half of Jupiter's orbital distance from the Sun. The source stars are slightly evolved, and by requiring them to lie on the same isochrone, we can constrain the source to lie in the near side of the bulge at a distance of DS=6.8±0.6kpc, which implies a distance to the planetary lens system of DL=3.4±0.2kpc. The ability to model unusual planetary microlensing events, like this one, will be necessary to extract precise statistical information from the planned large exoplanet microlensing surveys, such as the WFIRST microlensing survey.

_________________
Caps Lock: Cruise control for 'Cool'!