Theories of planet formation predict the existence of a population of free-floating planets that are not gravitationally tethered to any host star. Gravitational microlensing provides a unique tool for studying these objects. The first results of Sumi et al. (2011) claimed that Jupiter-mass free-floating planets are as common as main-sequence stars. However, these results disagree with censuses of substellar objects in young clusters and star-forming regions and with predictions of planet formation theories. I will present new results of the analysis of a ten times larger sample of microlensing events discovered by the OGLE-IV survey during the years 2010-2015, which shed new light on the population of free-floating planets. I will also discuss prospects for detecting free-floating planets with the future missions, like Euclid and WFIRST.

BIO
Przemek Mroz is a PhD student at the Warsaw University Astronomical Observatory, Poland and is a member of the OGLE (Optical Gravitational Lensing Experiment) team. His research interests include astrophysical applications of gravitational microlensing (exoplanets, Galactic structure), transients, and variable stars. He received the prestigious START fellowship of the Foundation for Polish Science and the 'Young Scientist Award' of the Polish Astronomical Society.