John C. Geary
A5052085877- Stellar, planetary, and galactic studies
- Astro and Planetary Science
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- CCD and CMOS Imaging Sensors
- Adaptive optics and wavefront sensing
- Astronomical Observations and Instrumentation
- Planetary Science and Exploration
- Infrared Target Detection Methodologies
- Calibration and Measurement Techniques
- Gamma-ray bursts and supernovae
- Geomagnetism and Paleomagnetism Studies
- Space Exploration and Technology
- History and Developments in Astronomy
- Photocathodes and Microchannel Plates
- Geology and Paleoclimatology Research
- Particle Accelerators and Free-Electron Lasers
- Spectroscopy Techniques in Biomedical and Chemical Research
- Semiconductor Lasers and Optical Devices
- Geophysics and Gravity Measurements
- Methane Hydrates and Related Phenomena
- Advanced Semiconductor Detectors and Materials
- Advanced Sensor Technologies Research
- Pulsed Power Technology Applications
- Optical Systems and Laser Technology
Center for Astrophysics Harvard & Smithsonian
2014-2024
Smithsonian Astrophysical Observatory
1996-2020
Harvard University
1980-2014
Harvard University Press
1998-2012
The Kepler mission was designed to determine the frequency of Earth-sized planets in and near habitable zone Sun-like stars. is region where planetary temperatures are suitable for water exist on a planet's surface. During first 6 weeks observations, monitored 156,000 stars, five new exoplanets with sizes between 0.37 1.6 Jupiter radii orbital periods from 3.2 4.9 days were discovered. density Neptune-sized Kepler-4b similar that Neptune GJ 436b, even though irradiation level 800,000 times...
A survey that can cover the sky in optical bands over wide fields to faint magnitudes with a fast cadence will enable many of exciting science opportunities next decade. The Large Synoptic Survey Telescope (LSST) have an effective aperture 6.7 meters and imaging camera field view 9.6 deg^2, be devoted ten-year 20,000 deg^2 south +15 deg. Each pointing imaged 2000 times fifteen second exposures six broad from 0.35 1.1 microns, total point-source depth r~27.5. LSST Science Book describes basic...
On 2011 February 1 the Kepler mission released data for 156,453 stars observed from beginning of science observations on 2009 May 2 through September 16. There are 1235 planetary candidates with transit-like signatures detected in this period. These associated 997 host stars. Distributions characteristics separated into five class sizes: 68 approximately Earth-size (Rp < 1.25 R⊕), 288 super-Earth-size (1.25 R⊕ ⩽ Rp 662 Neptune-size (2 6 165 Jupiter-size (6 15 and 19 up to twice size Jupiter...
New transiting planet candidates are identified in 16 months (2009 May-2010 September) of data from the Kepler spacecraft.Nearly 5000 periodic transit-like signals vetted against astrophysical and instrumental false positives yielding 1108 viable new candidates, bringing total count up to over 2300.Improved vetting metrics employed, contributing higher catalog reliability.Most notable is noise-weighted robust averaging multiquarter photo-center offsets derived difference image analysis that...
The Kepler Mission, launched on 2009 March 6, was designed with the explicit capability to detect Earth-size planets in habitable zone of solar-like stars using transit photometry method. Results from just 43 days data along ground-based follow-up observations have identified five new transiting measurements their masses, radii, and orbital periods. Many aspects stellar astrophysics also benefit unique, precise, extended, nearly continuous set for a large number variety stars. Early results...
We report the detection of a planet whose orbit surrounds pair low-mass stars. Data from Kepler spacecraft reveal transits across both stars, in addition to mutual eclipses giving precise constraints on absolute dimensions all three bodies. The is comparable Saturn mass and size, nearly circular 229-day around its two parent eclipsing stars are 20% 69% as massive sun, have an eccentric 41-day orbit. motions bodies confined within 0.5 degree single plane, suggesting that formed circumbinary disk.
We report on the orbital architectures of Kepler systems having multiple-planet candidates identified in analysis data from first six quarters and reported by Batalha et al. (2013). These show 899 transiting planet 365 provide a powerful means to study statistical properties planetary systems. Using generic mass–radius relationship, we find that only two pairs planets these candidate (out 761 total) appear be Hill-unstable orbits, indicating ∼96% are correctly interpreted as true little...
The Kepler spacecraft is monitoring more than 150,000 stars for evidence of planets transiting those stars. We report the detection two Saturn-size that transit same Sun-like star, based on 7 months observations. Their 19.2- and 38.9-day periods are presently increasing decreasing at respective average rates 4 39 minutes per orbit; in addition, times inner body display an alternating variation smaller amplitude. These signatures characteristic gravitational interaction near a 2:1 orbital...
In the Solar system planets' compositions vary with orbital distance, rocky planets in close orbits and lower-density gas giants wider orbits. The detection of close-in giant around other stars was first clue that this pattern is not universal, can change substantially after their formation. Here we report another violation orbit-composition pattern: two orbiting same star distances differing by only 10%, densities a factor 8. One planet likely `super-Earth', whereas more akin to Neptune....
In the spring of 2009, Kepler Mission commenced high-precision photometry on nearly 156,000 stars to determine frequency and characteristics small exoplanets, conduct a guest observer program, obtain asteroseismic data wide variety stars. On 15 June 2010 released from first quarter observations. At time this publication, 706 set have exoplanet candidates with sizes as that Earth larger than Jupiter. Here we give identity 306 planetary candidates. Data for remaining 400 will be in February...
We report the detection of Kepler-47, a system consisting two planets orbiting around an eclipsing pair stars. The inner and outer have radii 3.0 4.6 times that Earth, respectively. binary star consists Sun-like companion roughly one-third its size, each other every 7.45 days. With orbital period 49.5 days, eighteen transits planet been observed, allowing detailed characterization orbit those planet's is 303.2 although not Earth-like, it resides within classical "habitable zone", where...
The Hectospec is a 300 optical fiber fed spectrograph commissioned at the MMT in spring of 2004. In configuration pioneered by Autofib instrument Anglo‐Australian Telescope, Hectospec's probes are arranged radial "fisherman on pond" geometry and held position with small magnets. A pair high‐speed, six‐axis robots move buttons between observing configurations within ∼300 s, to an accuracy ∼25 μm. fibers run for 26 m MMT's focal surface bench spectrograph, operating R∼1000–2000. Hectochelle,...
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...
A search of the time-series photometry from NASA's Kepler spacecraft reveals a transiting planet candidate orbiting 11th magnitude G5 dwarf KIC 10593626 with period 290 days. The characteristics host star are well constrained by high-resolution spectroscopy combined an asteroseismic analysis photometry, leading to estimated mass and radius 0.970 ± 0.060 M☉ 0.979 0.020 R☉. depth 492 10 ppm for three observed transits yields 2.38 0.13 Re planet. system passes battery tests false positives,...
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 a statistical analysis that demonstrates the overwhelming majority of Kepler candidate multiple transiting systems (multis) indeed represent true, physically associated planets. Binary stars provide primary source false positives among planet candidates, implying should be nearly randomly distributed targets. In contrast, true planets would appear clustered around smaller number targets if detectable tend to come in and/or orbital planes encircling same star are correlated. There...
Eighty planetary systems of two or more planets are known to orbit stars other than the Sun. For most, data can be sufficiently explained by non-interacting Keplerian orbits, so dynamical interactions these have not been observed. Here we present 4 sets lightcurves from Kepler spacecraft, which each show multiple transiting same star. Departure timing transits strict periodicity indicates perturbing other: observed variations match forcing frequency planet. This confirms that objects in...
We discuss the discovery and characterization of circumbinary planet Kepler-38b. The stellar binary is single-lined, with a period 18.8 days, consists moderately evolved main-sequence star (M_A = 0.949 +/- 0.059 solar masses R_A 1.757 0.034 radii) paired low-mass (M_B 0.249 0.010 R_B 0.2724 0.0053 in mildly eccentric (e=0.103) orbit. A total eight transits due to crossing primary were identified Kepler light curve (using Quarters 1 through 11), from which planetary 105.595 0.053 days can be...
We present the Kepler Object of Interest (KOI) catalog transiting exoplanets based on searching four years time series photometry (Data Release 25, Q1-Q17). The contains 8054 KOIs which 4034 are planet candidates with periods between 0.25 and 632 days. Of these candidates, 219 new in this include two multi-planet systems (KOI-82.06 KOI-2926.05), ten high-reliability, terrestrial-size, habitable zone candidates. This was created using a tool called Robovetter automatically vets DR25 Threshold...
We describe a high‐throughput optical spectrograph that has been in operation at the Cassegrain focus of 1.5‐m Tillinghast reflector since 1994 January. FAST 3 '‐long slit and is typically operated resolutions between 1 6 Å. With collimated beam diameter ∼100 mm, (with 300 lines mm−1 grating 15‐wide slit) offers 4000 Å spectral coverage resolution. FAST's optics are primarily reflective, adequately sized to prevent vignetting, use high‐performance coatings. The high measured system peak...
Ten days of photometric data were obtained during the commissioning phase Kepler mission, including for previously known giant transiting exoplanet HAT-P-7b. The HAT-P-7b show a smooth rise and fall light from planet as it orbits its star, punctuated by drop 130 +/- 11 parts per million in flux when passes behind star. We interpret this variation dayside thermal emission plus reflected star is occulted. depth occultation similar precision to detection Earth-size which mission was designed.