A5028039404- Astro and Planetary Science
- Stellar, planetary, and galactic studies
- Geological and Geochemical Analysis
- High-pressure geophysics and materials
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Planetary Science and Exploration
- Geochemistry and Geologic Mapping
- Geology and Paleoclimatology Research
- Hydrocarbon exploration and reservoir analysis
- earthquake and tectonic studies
- Paleontology and Stratigraphy of Fossils
- Solidification and crystal growth phenomena
- Geological and Geophysical Studies
- Atmospheric Ozone and Climate
- Crystal Structures and Properties
- Methane Hydrates and Related Phenomena
- Metallurgical Processes and Thermodynamics
- demographic modeling and climate adaptation
- Gender Diversity and Inequality
- Data Visualization and Analytics
- Space Exploration and Technology
- Phase Equilibria and Thermodynamics
- CO2 Sequestration and Geologic Interactions
- Glass properties and applications
Search for Extraterrestrial Intelligence
2023-2024
University of Michigan
2014-2023
California Institute of Technology
2007-2015
Zero to Three
2009
University of California, Santa Cruz
2005-2007
Doppler measurements from Subaru and Keck have revealed radial velocity variations in the V=8.15, G0IV star HD 149026 consistent with a Saturn-Mass planet 2.8766 day orbit. Photometric observations at Fairborn Observatory detected three complete transit events depths of 0.003 mag predicted times conjunction. is now second brightest transiting extrasolar planet. The mass star, based on interpolation stellar evolutionary models, 1.3 +/- 0.1 solar masses; together amplitude, K=43.3 m s^-1, we...
Secondary eclipse spectroscopy provides invaluable insights into the temperatures and compositions of exoplanetary atmospheres. We carry out a systematic temperature abundance retrieval analysis nine exoplanets (HD 189733b, HD 209458b, 149026b, GJ436b, WASP-12b, WASP-19b, WASP-43b, TrES-2b, TrES-3b) observed in secondary using combination space- ground-based facilities. Our goal with this is to provide consistent set from which self-consistent models can be compared probe underlying...
We have created specialized target lists for radial velocity surveys that are biased toward stars (1) possess planets and (2) easiest to observe with current detection techniques. use a procedure uniformly estimates fundamental stellar properties of Tycho 2 stars, errors, using spline functions broadband photometry proper motion found in Hipparcos/Tycho 2MASS. provide Teff distance 2.4 × 106 lack trigonometric distances. For appear be FGK dwarfs, we also derive [Fe/H] identify unresolved...
Accurately understanding the interior structure of extra-solar planets is critical for inferring their formation and evolution. The internal density distribution a planet has direct effect on star-planet orbit through gravitational quadrupole field created by rotational tidal bulges. These quadrupoles induce apsidal precession that proportional to planetary Love number ($k_{2p}$, twice motion constant), bulk physical characteristic depends distribution, including presence or absence massive...
Exoplanet atmosphere spectroscopy enables us to improve our understanding of exoplanets just as remote sensing in own solar system has increased the bodies. The challenge is quantitatively determine range temperatures and molecular abundances allowed by data, which often difficult given low information content most exoplanet spectra that commonly leads degeneracies interpretation. A variety spectral retrieval approaches have been applied spectra, but no previous investigations sought compare...
We present the systemic Console, a new all-in-one, general-purpose software package for analysis and combined multiparameter fitting of Doppler radial velocity (RV) transit timing observations. give an overview computational algorithms implemented in describe tools offered streamlining characterization planetary systems. illustrate capabilities by analyzing updated data set HD128311 system. harbors pair planets that appear to be participating 2:1 mean motion resonance. show dynamical...
Context. A terrestrial planet is molten during formation and may remain due to intense insolation or tidal forces. Observations favour the detection characterisation of hot planets, potentially with large outgassed atmospheres. Aims. We aim determine radius Earth-like planets outgassing Our goal explore differences between solid silicate on mass–radius relationship transmission emission spectra. Methods. An interior–atmosphere model was combined static structure calculations track evolving a...
Silicate vapors play a key role in planetary evolution, especially dominating early stages of rocky planet formation through outgassed magma ocean atmospheres. Our open-source thermodynamic modeling software "VapoRock" combines the MELTS liquid model (Ghiorso et al., 1995) with gas-species properties from multiple thermochemistry tables (e.g., Chase 1998). VapoRock calculates partial pressures 34 gaseous species equilibrium magmatic system Si-Mg-Fe-Al-Ca-Na-K-Ti-Cr-O at desired temperatures...
We report 35 radial velocity measurements of HD 149026 taken with the Keck Telescope. Of these measurements, 15 were made during transit companion planet 149026b, which occurred on 2005 June 25. These velocities provide a high-cadence observation Rossiter-McLaughlin effect, shifting photospheric line profiles that occurs when occults portion rotating stellar surface. combine previously published and photometric data sets derive composite best-fit model for star-planet system. This confirms...
Ontario Lacus is the largest and best characterized lake in Titan's south polar region. In June July 2009, Cassini RADAR acquired its first Synthetic Aperture Radar (SAR) images of area. Together with closest approach altimetry December 2008, these observations provide a unique opportunity to study lake's nearshore bathymetry complex refractive properties. Average radar backscatter observed decrease exponentially distance from local shoreline. This behavior consistent attenuation through...
Abstract The high‐pressure/high‐temperature equation of state (EOS) synthetic 13% Fe‐bearing bridgmanite (Mg silicate perovskite) is measured using powder X‐ray diffraction in a laser‐heated diamond anvil cell with quasi‐hydrostatic neon pressure medium. We compare these results, which are consistent previous 300 K sound speed and compression studies, reanalysis Fe‐free Mg end‐member data from Tange et al. (2012) to determine the effect iron on bridgmanite's thermoelastic properties. EOS...
Two extrasolar planets, HD 209458b and TrES-1, are currently known to transit bright parent stars for which physical properties can be accurately determined. The two transiting planets have very similar masses periods hence invite detailed comparisons between their observed theoretically predicted properties. In this paper, we carry out these comparisons. We first report photometric spectroscopic follow-up observations of use obtain improved estimates the planetary radius, Rpl = (1.08 ±...
We present an updated analysis of the GJ 876 planetary system based on augmented data set that incorporates 65 new high-precision radial velocities obtained with Keck Telescope from 2001 to 2004. These permit a more accurate characterization planet-planet interactions exhibited by system. Self-consistent three-body orbital fits (which incorporate both estimated instrumental uncertainties and Gaussian stellar jitter σ = 6 m s-1) continue show b (the outer planet system), c inner system) are...
Abstract The response of the carbon cycle in prognostic Earth system models (ESMs) contributes significant uncertainty to projections global climate change. Quantifying contributions known drivers interannual variability growth rate atmospheric dioxide (CO 2 ) is important for improving representation terrestrial ecosystem processes these ESMs. Several recent studies have identified temperature dependence tropical net exchange (NEE) as a primary driver this by analyzing single, globally...
Abstract To understand the impact cratering record on Venus, we investigate two distinct resurfacing styles: localized, thin flows and large shield volcanoes. We statistically analyze size‐frequency distribution of volcanically modified craters and, using Monte Carlo simulations, their spatial distribution. Lava partially fill most craters, darkening floors in radar images. find that a model featuring occurring throughout geologic time predicts observed Individual may be morphologically...
We report the results of a globally coordinated photometric campaign to search for transits by P ~ 30 d and 60 outer planets 3-planet system orbiting nearby M-dwarf Gl 876. These two experience strong mutual perturbations, which necessitate use dynamical (four-body) model compute transit ephemerides system. Our data have been collected from published archival sources, as well our campaigns that were targeted specific predictions. analysis indicates planet "c" (P d) do not currently occur, in...
Abstract Our study examines youth attitudes towards unions over a 40‐year period to try and understand whether today's young workers might be the ‘hero’ or ‘villain’ in tale of declining union membership rates United States. Using nationally representative time‐lag data from high‐school seniors ( N = 104,742) spanning 1976–2015, we conducted time trend, birth cohort generational analyses provide an ‘apples apples’ comparison how have felt about at different points time. We found that...
Abstract MESSENGER observations suggest a magma ocean formed on proto-Mercury, during which evaporation of metals and outgassing C- H-bearing volatiles produced an early atmosphere. Atmospheric escape subsequently occurred by plasma heating, photoevaporation, Jeans escape, photoionization. To quantify atmospheric loss, we combine constraints the lifetime surficial melt, melt composition, composition. Consideration two initial Mercury sizes four compositions determines speciation at given...