Speaker
Description
Planets are known to ubiquitous around low-mass stars ($M \gtrsim 80$ $M_J$), and in our solar system, moons far outnumber the gas giant planets ($M \lesssim 1$ $M_J$) they orbit. But do rogue worlds, with masses in between our solar system planets and the lowest-mass stars, host orbiting bodies of their own? I will describe our team's work to observationally probe the population of small companions (which we call "exosatellites") around free-floating planetary mass objects. Our strategy is to search for transits of these small bodies in infrared light curves of free-floating planets. So far, we have used Spitzer data to place constraints on the occurrence rate of terrestrial and sub-Neptune-sized exosatellites around substellar worlds, and have demonstrated exquisite sensitivity to Io analogs with JWST light curves of planetary-mass objects. I will present a first look at a data from a new JWST program to perform simultaneous photometric monitoring of 50 substellar objects to study variability and look for transits. And finally, we will discuss the promise for the Roman space telescope to dramatically expand the search for exosatellites to hundreds of rogue worlds and measure on the prevalence of small companions around planetary mass objects.
