A Pilot Radio Search for Magnetic Activity in Directly Imaged Exoplanets

Presenter: Dr. Yvette Cendes (Harvard-Smithsonian Center for Astrophysics)

Radio observations are a promising means to probe and measure magnetic fields in exoplanets, which could yield insights on topics ranging from exoplanet internal structure to habitability. However, most searches to date have only yielded upper limits, and focus in the MHz range, based on solar system analogs. In this talk, I will present the first systematic search for GHz frequency radio emission from directly imaged exoplanets using Very Large Array (VLA) observations of sufficient angular resolution to separate the planets from their host stars. I will discuss the obtained results for five systems and eight exoplanets located at less than 50 pc through observations and archival data, and how our limits are comparable to the level of radio emission detected in several ultracool dwarfs detected with the VLA, including T dwarfs, whose masses are only a factor of two times higher than those of the directly-imaged exoplanets but have similar effective temperatures. I will also highlight the need for continued GHz frequency radio observations of nearby exoplanets at microJansky-level sensitivity.