Andrew J. Skemer

197 CANDIDATES AND 104 VALIDATED PLANETS IN K2's FIRST FIVE FIELDS

NASA through the Sagan Fellowship Program; NASA through a Hubble Fellowship - Space Telescope Science Institute; NASA [NAS 5-26555, NNH14CK55B]; National Science Foundation Graduate Research Fellowship [2014184874]; FONDECYT [1130857]; BASAL CATA [PFB-06]; Ministry for the Economy, Development, and Tourisms Programa Iniciativa Cientifica Milenio [IC 120009]; Alfred P. Sloan Foundation; National Science Foundation [AST-0906060, AST-0960343, AST-1207891]; Mt. Cuba Astronomical Foundation; Max Planck Institute for Astronomy; Heidelberg; Max Planck Institute for Extraterrestrial Physics, Garching; Johns Hopkins University; Durham University; University of Edinburgh; Queens University Belfast; Harvard-Smithsonian Center for Astrophysics; Las Cumbres Observatory Global Telescope Network Incorporated; National Central University of Taiwan; Space Telescope Science Institute; National Aeronautics and Space Administration [NNX08AR22G]; University of Maryland; Eotvos Lorand University (ELTE)

On-sky operations and performance of LMIRcam at the Large Binocular Telescope

The L/M-band (3−5 μm) InfraRed Camera (LMIRcam) sits at the combined focal plane of the Large Binocular Telescope Interferometer (LBTI), ultimately imaging the coherently combined focus of the LBT’s two 8.4-meter mirrors. LMIRcam achieved first light at the LBT in May 2011 using a single AO-enabled 8.4-meter aperture. With the delivery of LBT’s final adaptive secondary mirror in Fall of 2011, dual-aperture AO-corrected interferometric fringes were realized in April 2012. We report on the performance of these configurations and characterize the noise performance of LMIRcam’s HAWAII-2RG 5.3-μm cutoff array paired with Cornell FORCAST readout electronics. In addition, we describe recent science highlights and discuss future improvements to the LMIRcam hardware.

The Gemini NICI planet-finding campaign: The orbit of the young exoplanet β pictoris b

We present new astrometry for the young (12-21 Myr) exoplanet beta Pictoris b taken with the Gemini/NICI and Magellan/MagAO instruments between 2009 and 2012. The high dynamic range of our observations allows us to measure the relative position of beta Pic b with respect to its primary star with greater accuracy than previous observations. Based on a Markov Chain Monte Carlo analysis, we find the planet has an orbital semi-major axis of 9.1 (+ 5.3 / - 0.5) AU and orbital eccentricity less than 0.15 at 68% confidence (with 95% confidence intervals of 8.2 - 48 AU and 0.00 - 0.82 for semi-major axis and eccentricity, respectively, due to a long narrow degenerate tail between the two). We find that the planet has reached its maximum projected elongation, enabling higher precision determination of the orbital parameters than previously possible, and that the planets projected separation is currently decreasing. With unsaturated data of the entire beta Pic system (primary star, planet, and disk) obtained thanks to NICIs semitransparent focal plane mask, we are able to tightly constrain the relative orientation of the circumstellar components. We find the orbital plane of the planet lies between the inner and outer disks: the position angle (P.A.) of nodes for the planets orbit (211.8 +/- 0.3 deg) is 7.4 sigma greater than the P.A. of the spine of the outer disk and 3.2 sigma less than the warped inner disk P.A., indicating the disk is not collisionally relaxed. Finally, for the first time we are able to dynamically constrain the mass of the primary star beta Pic to 1.76 (+0.18 / -0.27) solar mass.

ON THE MORPHOLOGY AND CHEMICAL COMPOSITION OF THE HR 4796A DEBRIS DISK

[abridged] We present resolved images of the HR 4796A debris disk using the Magellan adaptive optics system paired with Clio-2 and VisAO. We detect the disk at 0.77 \microns, 0.91 \microns, 0.99 \microns, 2.15 \microns, 3.1 \microns, 3.3 \microns, and 3.8 \microns. We find that the deprojected center of the ring is offset from the star by 4.76

The LEECH Exoplanet Imaging Survey: Characterization of the Coldest Directly Imaged Exoplanet, GJ 504 b, and Evidence for Superstellar Metallicity

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INDICATIONS OF WATER CLOUDS IN THE COLDEST KNOWN BROWN DWARF

1.6 AU and that the deprojected eccentricity is 0.06

HIGH-CADENCE, HIGH-CONTRAST IMAGING for EXOPLANET MAPPING: OBSERVATIONS of the HR 8799 PLANETS with VLT/SPHERE SATELLITE-SPOT-CORRECTED RELATIVE PHOTOMETRY

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Two Small Temperate Planets Transiting Nearby M Dwarfs in K2 Campaigns 0 and 1

0.02, in general agreement with previous studies. We find that the average width of the ring is 14

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

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TARGET SELECTION FOR THE LBTI EXOZODI KEY SCIENCE PROGRAM

, also comparable to previous measurements. Such a narrow ring precludes the existence of shepherding planets more massive than \about 4 \mj, comparable to hot-start planets we could have detected beyond \about 60 AU in projected separation. Combining our new scattered light data with archival HST/STIS and HST/NICMOS data at \about 0.5-2 \microns, along with previously unpublished Spitzer/MIPS thermal emission data and all other literature thermal data, we set out to constrain the chemical composition of the dust grains. After testing 19 individual root compositions and more than 8,400 unique mixtures of these compositions, we find that good fits to the scattered light alone and thermal emission alone are discrepant, suggesting that caution should be exercised if fitting to only one or the other. When we fit to both the scattered light and thermal emission simultaneously, we find mediocre fits (reduced chi-square \about 2). In general, however, we find that silicates and organics are the most favored, and that water ice is usually not favored. These results suggest that the common constituents of both interstellar dust and solar system comets also may reside around HR 4796A, though improved modeling is necessary to place better constraints on the exact chemical composition of the dust.