High contrast imaging at the LBT: the LEECH exoplanet imaging survey

摘要

In Spring 2013, the LEECH (LBTI Exozodi Exoplanet Common Hunt) survey began its ～130-night campaign from the Large Binocular Telescope (LBT) atop Mt Graham, Arizona. This survey benefits from the many technological achievements of the LBT, including two 8.4-meter minors on a single fixed mount, dual adaptive secondary mirrors for high Strehl performance, and a cold beam combiner to dramatically reduce the telescope's overall background emissivity. LEECH neatly complements other high-contrast planet imaging efforts by observing stars at L' (3.8 μm), as opposed to the shorter wavelength near-infrared bands (1-2.4 μm) of other surveys. This portion of the spectrum offers deep mass sensitivity, especially around nearby adolescent (～0.1-l Gyr) stars. LEECH's contrast is competitive with other extreme adaptive optics systems, while providing an alternative survey strategy. Additionally, LEECH is characterizing known exoplanetary systems with observations from 3-5μm in preparation for JWST.