Open access

Exploring the Formation and Evolution of Planetary Systems
ProceedingsIAU SymposiumNo.299, 2013
M. Booth, B. C. Matthews &J. R. Graham, eds.
c
International Astronomical Union 2013
doi:10.1017/S1743921313007928
LEECH: A100 NightExoplanet Imaging
Surveyat the LBT
Andrew Skemer1,DanielApai
1,Vanessa Bailey1,Beth Biller2,
Mickael Bonnefoy2,Wolfgang Brandner2,Esther Buenzli2,Laird
Close1,Justin Crepp3,Denis Defrere1,Silvano Desidera4,Josh
Eisner1,Simone Esposito5,Jonathan Fortney6,Thomas Henning2,
Phil Hinz1,Karl-Heinz Hofmann7,Jarron Leisenring1,8,Jared Males1,
Rafael Millan-Gabet9,Katie Morzinski1,ApurvaOza10,Ilaria
Pascucci11,JennyPatience12,George Rieke1,Dieter Schertl7,Joshua
Schlieder2,MikeSkrutskie10,KateSu
1,Gerd Weigelt7,CharlesE.
Woodward13 and Neil Zimmerman2
1Steward Observatory,DepartmentofAstronomy,UniversityofArizona
2MaxPlanckInstitute for Astronomy
3Departmentof Physics, Notre DameUniversity
4OsservatorioAstronomicodiPadova, Istituto NazionalediAstrofisica
5OsservatorioAstrofisico di Arcetri,Istituto Nazionaledi Astrofisica
6Departmentof Astronomyand Astrophysics, UniversityofCalifornia, SantaCruz
7MaxPlanckInstitute for Radio Astronomy
8Institute for Astronomy,Eldgenossische Technische HochschuleZurich
9NASAExoplanet Science Institute, CaliforniaInstitute of Technology
10Departmentof Astronomy,Universityof Virginia
11Departmentof Planetary Sciences, Lunar and Planetary Laboratory,Universityof Arizona
12School of Earth and Space Exploration, Arizona State University
13Minnesota Institute for Astrophysics, UniversityofMinnesota
Abstract.In February 2013, the LEECH(LBTIExozodiExoplanet CommonHunt) survey be-
gan its100-nightcampaignfrom the Large Binocular Telescopeatop MountGraham inArizona.
LEECHneatlycomplements other high-contrast planet imaging efforts byobservingstars inL’
band (3.8microns) as opposed tothe shorter wavelength near-infrared bands (1–2.3microns).
Thispart of the spectrum offers deeper mass sensitivityfor intermediate age (several hundred
Myr-old) systems, since theirJovian-mass planets radiate predominantlyinthe mid-infrared.
In thisproceedings, wepresentthe science goalsfor LEECHand apreliminary contrast curve
from someearlydata.
Keywords.instrumentation: adaptiveoptics, (stars:) planetary systems, surveys
Discovering AdolescentExoplanets: Most exoplanet imaging surveys operate in
the near-infrared (H-band; 1.65 µm), which provides the best contrasts at small separa-
tions. However, self-luminous exoplanets emit most oftheir lightatlonger wavelengths,
and this becomes more importantasexoplanets age and lose the residual energy from
their formation. Byoperating inthe mid-infrared (L; 3.8 µm) LBTI is sensitivetoplanets
around older stars (see Figure 1). This will allowLEECH todiscoveradolescentexoplan-
ets around nearbystars, complementing the young samples discovered byother surveys
(see Figure 2), suchas GPI, SPHERE, SEEDS, and Project 1640 (Macintosh et al. 2008,
Beuzit et al. 2008, Tamura 2009, Hinkley et al. 2011)
Connecting Planets with Disks: Using the twoLBTI science cameras in parallel,
LEECH and HOSTS (see paper byDefrere et al. in these proceedings) will searchfor
giantplanets and inner debris disks simultaneously.The LEECH and HOSTS samples
include very nearbystars that havebeen targeted byother relevantsurveys (Doppler-RV
70

LEECH 71
Figure 1. LEFT:Afirst lightimage from LEECHwiththe star removedand an artificialplanet
inserted. The artificialplanet is13 magnitudes fainter than the star ataseparation of 0.75′′ ,
equivalentto a 3 Mjup planet 7.5AU froma 0.5Gyrsolartypestarat10 pc. LEECH’sability
to image older exoplanets than other surveys will extend our knowledge of exoplanet evolution.
RIGHT:ADI+PCA(KLIP)detectionlimits forabrightstarwith 2hoursintegrationtimeon
1telescope(preliminary).
Figure 2. Planet mass versus semi-major axisforthe knownexoplanets and planetary mass
companions listedinwww.exoplanet.eushownas small circlesfor radialvelocitydetections,
large circles forimaging, and stars for imaged planets around HR8799, βPic, and Fomalhaut.
The median planet mass sensitivities are shown forthe GPIA-and F-star sample,the LEECH
sample,and an A-star search(Vigan et al. 2012) with NaCo/NIRI. Both GPIand LEECH
will explorethecriticalmissinglinkbetween radialvelocitysearches and currentAOimaging
surveys.
planet searches and outer debris disk studies). Combining this data, will provide the first
comprehensiveview ofexoplanetary systems.
Characterizing Exoplanet Atmospheres: Early observations suggest that
directly imaged planets havedifferentcolors and spectra than their field brown-dwarf
analogs. Bystudying planets with LBTI’s broad wavelength coverage (1-13 µm) and
over awide age range, LEECH will characterize the bulk atmospheric properties and
evolution of extrasolar planets.
References
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Macintosh, B. A., Graham,J. R., Palmer, D.W., et al. 2008, SPIE,7015
Tamura, M.2009, AIPC,1158, 11
Vigan, A., Patience, J.,Marois, C., et al. 2012, A&A,544, A9