Imaging Exoplanets Around Accelerating Stars in the Gaia DR4 Era

Speaker: 
Kyle Franson
Institution: 
University of California, Santa Cruz
Date: 
Tuesday, November 10, 2026
Time: 
4:00 pm
Location: 
RH 160

Abstract: Directly imaged exoplanets offer unparalleled information on the atmospheres, architectures, and origins of gas giants on Solar System scales. Blind high-contrast imaging surveys of hundreds of stars have measured the demographics of this population and shown that wide-orbit giant planets are intrinsically rare, making each new discovery hard-won. This is poised to change. On December 2nd, Gaia DR4 will be released. The culmination of the 5.5-year Gaia prime mission, DR4 is expected to feature thousands of new astrometric giant planets and an order of magnitude more astrometric accelerations caused by planets and brown dwarfs on wider orbits. In parallel, new high-contrast instruments such as SCALES, HISPEC, and GPI 2.0 will reach smaller inner working angles and deeper contrasts. In this talk, I will discuss the opportunity Gaia DR4 presents for targeted searches to image new exoplanets. I will first share the results of the Astrometric Accelerations as Dynamical Beacons survey, which used Hipparcos and Gaia to significantly increase the efficiency of imaging new long-period planets. I will then describe how we are extending this approach to colder planets with JWST/MIRI and to Gaia DR4 targets with Keck/SCALES. Together, these programs usher in a new era of exoplanet imaging in which Gaia pinpoints the most promising targets, new instruments reach the planets behind these accelerations, and each discovery comes with a dynamical mass and is primed for follow-up orbital and atmospheric characterization.

Host: 
Paul Robertson