Determining the amount of dust in the habitable zone: a Keck Nuller survey of 26 nearby main sequence stars
Because of contrast limitations at high angular resolution, direct observations of debris disks have so far been restricted to the outer (> 10AU) parts of nearby solar systems. The Keck Interferometer Nuller (KIN) was specifically designed to push this limit, and constrain exo-zodiacal emission originating from the "rocky planet forming region", i.e. from 0.1 AU to a few AUs. The characterization of exo-zodiacal light at these spatial scales is very revealing as it reflects the host system’s specific distribution of planets, dust sources and sinks. Strong exo-zodi emission in the habitable zone is also important to identify, as it can be a hindrance to direct imaging of Earth-like exoplanets. We discuss here the results of a Keck Nuller exo-zodi program targeting 26 nearby main sequence stars, most of which with no previously known infrared excess.