Wednesday 29 Sep 2021: Hunting for Planets and Low-Mass Companions around Hot Stars: The ARMADA Survey at CHARA and VLTI
Tyler Gardner -
Current detection limits struggle to find exoplanets around hot (A/B-type) stars. Searching for planets in this regime provides crucial information on how planet occurrence rate scales with stellar mass. We are carrying out an interferometric survey to detect au-regime giant planets via differential astrometry orbiting individual stars of sub-arcsecond hot binary systems. The combination of milli-arcsecond resolution with stable wavelength calibration provides precision at the few tens of micro-arcsecond level in short observations at CHARA/MIRCX and VLTI/GRAVITY. This allows us to detect the wobble of a star from orbiting companions down to a few Jupiter masses. I will present the status of our survey and astrometric results, including newly detected tertiary stellar companions and some substellar candidate detections. We show that we are beginning to probe down to planetary masses on a number of targets with non-detections. This data will be used to constrain demographic models of low mass companions around hot stars.