Observational Constraints on Circumplanetary Material Orbiting a Young Exoplanet

Abstract

Astronomers' study of the formation and evolution of exoplanets has led them to explore the connection between disks of debris around stars and the presence of planetary companions, particularly orbiting M dwarfs. Among these fascinating systems, the AU Mic b exoplanet stands out as a potential target for studying circumplanetary material, which has not been conclusively directly observed before. This research aims to investigate the role of secondary thermal eclipses in assessing the presence of exoplanets with circumplanetary debris, to observationally constrain the relationship between planetary formation and circumstellar debris around young stars. The study of secondary eclipses, occurring when an exoplanet moves behind its parent star, presents a unique chance to directly assess the exoplanet's thermal radiation. Moreover, young stars with planetary companions will exhibit a unique thermal pattern during secondary eclipses, reflecting the presence of circumplanetary material surrounding the exoplanet. This is achieved by obtaining measurements of the emitted flux directly from the illuminated dayside of the planet during secondary eclipses, along with phase curves captured at various illumination angles. By comparing and contrasting the thermal characteristics of the primary and secondary eclipses, we expect to observe distinct thermal signals associated with the presence of circumplanetary debris. This research will pave the way for future understanding of exoplanetary systems and their formation.