Jordan M. Stone, The University of Arizona
Andrew J. Skemer, University of California, Santa Cruz
Philip M. Hinz, The University of Arizona
Mariangela Bonavita, University of Edinburgh, Institute for Astronomy
Kaitlin M. Kratter, The University of Arizona
Anne Lise Maire, Max Planck Institute for Astronomy
Denis Defrere, Université de Liège
Vanessa P. Bailey, Jet Propulsion Laboratory
Eckhart Spalding, The University of Arizona
Jarron M. Leisenring, The University of Arizona
S. Desidera, Osservatorio Astronomico di Padova
M. Bonnefoy, Université Grenoble Alpes
Beth Biller, University of Edinburgh, Institute for Astronomy
Charles E. Woodward, University of Minnesota Twin Cities
Th Henning, Max Planck Institute for Astronomy
Michael F. Skrutskie, University of Virginia
J. A. Eisner, The University of Arizona
Justin R. Crepp, University of Notre Dame
Jennifer Patience, School of Earth and Space Exploration
Gerd Weigelt, Max Planck Institute for Radio Astronomy
Robert J. De Rosa, University of California, Berkeley
Joshua Schlieder, Max Planck Institute for Astronomy
Wolfgang Brandner, Max Planck Institute for Astronomy
Dániel Apai, The University of Arizona
Kate Su, The University of Arizona
Steve Ertel, The University of Arizona
Kimberly Ward-Duong, Amherst CollegeFollow
Katie M. Morzinski, The University of Arizona
Dieter Schertl, Max Planck Institute for Radio Astronomy
Karl Heinz Hofmann, Max Planck Institute for Radio Astronomy
Laird M. Close, The University of Arizona
Stefan S. Brems, Landessternwarte Heidelberg

Document Type


Publication Date


Publication Title

Astronomical Journal


We present the results of the largest L' (3.8 μm) direct imaging survey for exoplanets to date, the Large Binocular Telescope Interferometer Exozodi Exoplanet Common Hunt (LEECH). We observed 98 stars with spectral types from B to M. Cool planets emit a larger share of their flux in L' compared to shorter wavelengths, affording LEECH an advantage in detecting low-mass, old, and cold-start giant planets. We emphasize proximity over youth in our target selection, probing physical separations smaller than other direct imaging surveys. For FGK stars, LEECH outperforms many previous studies, placing tighter constraints on the hot-start planet occurrence frequency interior to ~20 au. For less luminous, cold-start planets, LEECH provides the best constraints on giant-planet frequency interior to ~20 au around FGK stars. Direct imaging survey results depend sensitively on both the choice of evolutionary model (e.g., hot- or coldstart) and assumptions (explicit or implicit) about the shape of the underlying planet distribution, in particular its radial extent. Artificially low limits on the planet occurrence frequency can be derived when the shape of the planet distribution is assumed to extend to very large separations, well beyond typical protoplanetary dust-disk radii (≤50 au), and when hot-start models are used exclusively. We place a conservative upper limit on the planet occurrence frequency using coldstart models and planetary population distributions that do not extend beyond typical protoplanetary dust-disk radii. We find that ≤90% of FGK systems can host a 7-10 MJupplanet from 5 to 50 au. This limit leaves open the possibility that planets in this range are common.


Gaseous planets - stars, High angular resolution, Imaging - techniques, Planetary systems - planets and satellites










© 2018. The American Astronomical Society.


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