Imaging nearby, habitable-zone planets with the Large Binocular Telescope Interferometer

Abstract

One of the main design considerations of the Large Binocular Telescope (LBT) was the goal to resolve the habitable zones (HZs) of the nearest stars at mid-infrared wavelengths around 10 µm. The LBT Interferometer (LBTI) makes use of the telescope's two 8.4 m mirrors on a common mount and their 22.7 m edge-to-edge separation for sensitive, high-angular resolution observations at thermal-infrared wavelengths. In addition to adaptive optics imaging using the two mirrors separately, the instrument enables nulling and Fizeau imaging interferometry exploiting the full resolving power of the LBT. The LBTI team has successfully completed the Hunt for Observable Signatures of Terrestrial planetary Systems (HOSTS), for which we used nulling-interferometry to search for exozodiacal dust, and we are continuing the characterization of the detected systems. Here, we describe a new program to exploit the LBTI's Fizeau imaging interferometric capabilities for a deep imaging search for low-mass, HZ planets around a small sample of particularly suitable, nearby stars. We also review the LBTI's current status relevant to the proposed project to demonstrate the instrument is ready for such a large project.