Microlensing Finds Cool Exoplanets
Aparna Bhattacharya
University of Maryland, College Park

Microlensing is the only method currently that finds exoplanets as low mass as 5-earth mass at a wide orbit. These planets are cold and similar to our solar system cold planets, Jupiter and beyond. This method found ~>70 planets so far with ground based seeing limited survey telescopes. From these telescopes, we can get light curve models, which produces mass ratio between planet and host star. The source and lens host stars start separating out at a few mas/yr rate. Years (5-10) after the planets are detected, the two stars are separated by ~ 35 mas or above. At this point, we take high resolution Keck / HST data to image the host star and measure the mass of the host star as well as the planet. I will talk more details on this method. This is one of the primary method for detecting and measuring mass of solar system analog cold low mass wide orbit planets using future space telescope WFIRST, that is scheduled to launch in 2025.