Justin R. Crepp
A5091883312- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Astro and Planetary Science
- Adaptive optics and wavefront sensing
- Astronomical Observations and Instrumentation
- Gamma-ray bursts and supernovae
- Optical Systems and Laser Technology
- Astrophysical Phenomena and Observations
- Optical measurement and interference techniques
- Advanced optical system design
- High-pressure geophysics and materials
- Solar and Space Plasma Dynamics
- Advanced Fiber Laser Technologies
- Spacecraft Design and Technology
- CCD and CMOS Imaging Sensors
- Space Exploration and Technology
- Advanced Measurement and Metrology Techniques
- Optical Wireless Communication Technologies
- Geophysics and Gravity Measurements
- Optical Coatings and Gratings
- Planetary Science and Exploration
- Spacecraft and Cryogenic Technologies
- Optical Polarization and Ellipsometry
- Photonic Crystal and Fiber Optics
University of Notre Dame
2016-2025
History of Science Society
2012-2015
California Institute of Technology
2009-2013
Notre Dame University
2013
University of Florida
1994-2011
NASA Exoplanet Science Institute
2010-2011
Optica
2009
Pennsylvania State University
2004
ABSTRACT The Sloan Digital Sky Survey III (SDSS-III) presents the first spectroscopic data from Baryon Oscillation Spectroscopic (BOSS). This ninth release (DR9) of SDSS project includes 535,995 new galaxy spectra (median z ∼ 0.52), 102,100 quasar 2.32), and 90,897 stellar spectra, along with presented in previous releases. These were obtained BOSS spectrograph taken between 2009 December 2011 July. In addition, parameters pipeline, which determines radial velocities, surface temperatures,...
The Sloan Digital Sky Survey (SDSS) has been in operation since 2000 April. This paper presents the Tenth Public Data Release (DR10) from its current incarnation, SDSS-III. data release includes first spectroscopic Apache Point Observatory Galaxy Evolution Experiment (APOGEE), along with Baryon Oscillation Spectroscopic (BOSS) taken through 2012 July. APOGEE instrument is a near-infrared R ∼ 22,500 300 fiber spectrograph covering 1.514–1.696 μm. survey studying chemical abundances and radial...
Correlations between stellar properties and the occurrence rate of exoplanets can be used to inform target selection future planet-search efforts provide valuable clues about planet-formation process. We analyze a sample 1266 stars drawn from California Planet Survey targets determine empirical functional form describing likelihood star harboring giant planet as function its mass metallicity. Our ranges M dwarfs with masses low 0.2 M⊙ intermediate-mass subgiants high 1.9 M⊙. In agreement...
We report on the masses, sizes, and orbits of planets orbiting 22 Kepler stars. There are 49 planet candidates around these stars, including 42 detected through transits 7 revealed by precise Doppler measurements host Based an analysis brightness measurements, along with high-resolution imaging spectroscopy, (for 11 stars) asteroseismology, we establish low false-positive probabilities (FPPs) for all transiting (41 have FPP under 1%), constrain their sizes masses. Most smaller than three...
In this paper we search for distant massive companions to known transiting gas giant planets that may have influenced the dynamical evolution of these systems. We present new radial velocity observations a sample 51 obtained using Keck HIRES instrument, and find statistically significant accelerations in fifteen Six systems no previously reported published literature: HAT-P-10, HAT-P-22, HAT-P-29, HAT-P-32, WASP-10, XO-2. combine our fits with NIRC2 adaptive optics (AO) imaging data place...
We present the discovery of KELT-1b, first transiting low-mass companion from wide-field Kilodegree Extremely Little Telescope-North (KELT-North) survey. The V=10.7 primary is a mildly evolved, solar-metallicity, mid-F star. brown dwarf or super-massive planet with mass 27.23+/-0.50 MJ and radius 1.110+0.037-0.024 RJ, on very short period (P=1.21750007) circular orbit. KELT-1b receives large amount stellar insolation, an equilibrium temperature assuming zero albedo perfect redistribution...
The quest for Earth-like planets represents a major focus of current exoplanet research. While that are Earth-sized and smaller have been detected, these reside in orbits too close to their host star allow liquid water on surface. We present the detection Kepler-186f, 1.11+\-0.14 Earth radius planet is outermost five - all roughly transit 0.47+\-0.05 Rsun star. intensity spectrum star's radiation places Kepler-186f stellar habitable zone, implying if has an atmosphere H2O at its surface,...
We present the detection of five planets -- Kepler-62b, c, d, e, and f size 1.31, 0.54, 1.95, 1.61 1.41 Earth radii, orbiting a K2V star at periods 5.7, 12.4, 18.2, 122.4 267.3 days, respectively. The outermost (Kepler-62e & -62f) are super-Earth-size (1.25 < planet radius/earth radius 2.0) in habitable zone (HZ) their host star, receiving 1.2 +- 0.2 0.41 0.05 times solar flux Earth's orbit. Theoretical models Kepler-62e -62f for stellar age ~7 Gyr suggest that both could be solid: either...
We present the characterization of star KOI 961, an M dwarf with transit signals indicative three short-period exoplanets, originally discovered by Kepler Mission. proceed comparing 961 to Barnard's Star, a nearby, well-characterized mid-M dwarf. By colors, optical and near-infrared spectra, we find remarkable agreement between two, implying similar effective temperatures metallicities. Both are metal-poor compared Solar neighborhood, have low projected rotational velocity, high absolute...
We present a high-precision radial velocity (RV) survey of 719 FGKM stars, which host 164 known exoplanets and 14 newly discovered or revised substellar companions. This catalog updated the orbital parameters long-period candidates, some have decades-longer observational baselines than they did upon initial detection. The range from warm sub-Neptunes super-Earths to cold gas giants. sample selection criteria, as well over 100,000 RV measurements, come Keck-HIRES, APF-Levy, Lick-Hamilton...
We present 197 planet candidates discovered using data from the first year of NASA K2 mission (Campaigns 0-4), along with results an intensive program photometric analyses, stellar spectroscopy, high-resolution imaging, and statistical validation. distill these into sets 104 validated planets (57 in multi-planet systems), 30 false positives, 63 remaining candidates. Our systems span a range properties, median values R_P = 2.3 R_E, P=8.6 d, Tef 5300 K, Kp=12.7 mag. Stellar spectroscopy...
The Second Workshop on Extreme Precision Radial Velocities defined circa 2015 the state of art Doppler precision and identified critical path challenges for reaching 10 cm s−1 measurement precision. presentations discussion key issues instrumentation data analysis workshop recommendations achieving this bold are summarized here. Beginning with High Accuracy Velocity Planet Searcher spectrograph, technological advances radial velocity (RV) measurements have focused building extremely stable...
We conducted a Doppler survey at Keck combined with NIRC2 K-band AO imaging to search for massive, long-period companions 123 known exoplanet systems one or two planets detected using the radial velocity (RV) method. Our is sensitive Jupiter mass out 20 AU majority of stars in our sample, and we report discovery eight new planets, addition statistically significant RV trends indicating presence an outer companion beyond 5 AU. combine observations determine range allowed masses orbital...
Abstract We used high-precision radial velocity measurements of FGKM stars to determine the occurrence giant planets as a function orbital separation spanning 0.03–30 au. Giant are more prevalent at distances 1–10 au compared orbits interior or exterior this range. The increase in planet ∼1 by factor ∼4 is highly statistically significant. A fall-off larger favored over models with flat increasing occurrence. measure <?CDATA ${14.1}_{-1.8}^{+2.0}$?> <mml:math...
The A5V star Alcor has an M3–M4 dwarf companion, as evidenced by a novel astrometric technique. Imaging spectroscopy combined with adaptive optics coronagraphy allowed for the detection and spectrophotometric characterization of point source at contrast ∼6 J- H-band magnitudes separation 1'' from primary star. use pupil plane grid us to determine projected separations between companion coronagraphically occulted ⩽3 mas precision two observation epochs. Our measurements demonstrate common...
We report the discovery and confirmation of a transiting circumbinary planet (PH1b) around KIC 4862625, an eclipsing binary in Kepler field. The was discovered by volunteers searching first six Quarters publicly available data as part Planet Hunters citizen science project. Transits across larger brighter stars are detectable visual inspection every ~137 days, with seven transits identified 1-11. physical orbital parameters both host were obtained via photometric-dynamical model,...
We present the first secondary eclipse and phase curve observations for highly eccentric hot Jupiter HAT-P-2b in 3.6, 4.5, 5.8, 8.0 μm bands of Spitzer Space Telescope. The 3.6 4.5 data sets span an entire orbital period (P = 5.6334729 d), making them longest continuous obtained to date full-orbit a planet with eccentricity exceeding 0.2. improved non-parametric method removing intrapixel sensitivity variations at that robustly maps position-dependent flux variations. find peak planetary...
Small, cool planets represent the typical end-products of planetary formation. Studying architectures these systems, measuring planet masses and radii, observing planets' atmospheres during transit directly informs theories assembly, migration, evolution. Here we report discovery three small orbiting a bright (Ks = 8.6 mag) M0 dwarf using data collected as part K2, new ecliptic survey re-purposed Kepler spacecraft. Stellar spectroscopy K2 photometry indicate that system hosts transiting with...
The Kepler space telescope has opened new vistas in exoplanet discovery by revealing populations of Earth-sized planets that provide a context for understanding planet formation. Approximately 70% all stars the Galaxy belong to diminutive M dwarf class, several thousand which lie within Kepler's field view, and large number these targets show transit signals. Kepler-32 is typical star sample presents us with rare opportunity: five this giving an expansive view its architecture. All compact...
We obtained spectra in the wavelength range λ = 995–1769 nm of all four known planets orbiting star HR 8799. Using suite instrumentation as Project 1640 on Palomar 5 m Hale Telescope, we acquired data at two epochs. This allowed for multiple imaging detections companions and extractions low-resolution (R ∼ 35) spectra. Data reduction employed different methods speckle suppression spectrum extraction, both yielding results that agree. The do not directly correspond to those any objects,...
ABSTRACT Stellar companions can influence the formation and evolution of planetary systems, but there are currently few observational constraints on properties planet-hosting binary star systems. We search for stellar around 77 transiting hot Jupiter systems to explore statistical this population as compared field stars similar spectral type. After correcting survey incompleteness, we find that <?CDATA $47 \% \pm 7 $?> have with semimajor axes between 50 2000 au. This is 2.9 times larger...
Doppler-based planet surveys have discovered numerous giant planets but are incomplete beyond several AU. At larger star-planet separations, direct detection through high-contrast imaging has proven successful, this technique is sensitive only to young and characterization relies upon theoretical evolution models. Here we demonstrate that radial velocity measurements can be combined overcome these issues. The presence of widely separated companions deduced by identifying an acceleration...
We describe a new instrument that forms the core of long-term high contrast imaging program at 200 inch (5 m) Hale Telescope Palomar Observatory. The primary scientific thrust is to obtain images and low-resolution spectroscopy brown dwarfs young exoplanets several Jupiter masses in vicinity stars within 50 pc Sun. microlens-based integral field spectrograph integrated with diffraction-limited, apodized-pupil Lyot coronagraph. entire combination mounted behind adaptive optics (AO) system....
We present Kepler observations of the bright (V=8.3), oscillating star HD 179070. The show transit-like events which reveal that is orbited every 2.8 days by a small, 1.6 R_Earth object. Seismic studies 179070 using short cadence has frequencypower spectrum consistent with solar-like oscillations are acoustic p-modes. Asteroseismic analysis provides robust values for mass and radius 179070, 1.34{\pm}0.06 M{\circ} 1.86{\pm}0.04 R{\circ} respectively, as well yielding an age 2.84{\pm}0.34 Gyr...