A5015342505- Astro and Planetary Science
- Stellar, planetary, and galactic studies
- Astrophysics and Star Formation Studies
- Astronomy and Astrophysical Research
- Planetary Science and Exploration
- History and Developments in Astronomy
- Astronomical Observations and Instrumentation
- Astronomical and nuclear sciences
- Space Exploration and Technology
- Scientific Research and Discoveries
- Gamma-ray bursts and supernovae
- Space Science and Extraterrestrial Life
- Historical Astronomy and Related Studies
- Spacecraft and Cryogenic Technologies
- Solar and Space Plasma Dynamics
- Optical Wireless Communication Technologies
- Space Satellite Systems and Control
- Molecular Spectroscopy and Structure
- Adaptive optics and wavefront sensing
- Quantum chaos and dynamical systems
- Cold Atom Physics and Bose-Einstein Condensates
- Plant Diversity and Evolution
- Isotope Analysis in Ecology
- Phytochemical Studies and Bioactivities
- High-pressure geophysics and materials
University of Hawaiʻi at Mānoa
2014-2024
Planetary Science Institute
2021-2024
University of Hawaii System
2011-2023
International Franchise Association
2021
NASA Astrobiology Institute
2006-2015
Heidelberg Institute for Theoretical Studies
2015
Monterey Institute for Research in Astronomy
2014
University of Tübingen
2013-2014
Ames Research Center
2007
University of Washington
2007
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...
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...
The NASA Kepler mission has discovered thousands of new planetary candidates, many which have been confirmed through follow-up observations. A primary goal the is to determine occurrance rate terrestrial-size planets within Habitable Zone (HZ) their host stars. Here we provide a list HZ exoplanet candidates from Data Release 24 Q1-Q17 data vetting process. This work was undertaken as part Working Group. We use variety criteria regarding boundaries and sizes produce complete lists including...
Models of terrestrial planet formation for our solar system have been successful in producing planets with masses and orbits similar to those Venus Earth. However, these models generally failed produce Mars-sized objects around 1.5 AU. The body that is usually formed Mars' semimajor axis is, general, much more massive than Mars. Only when Jupiter Saturn are assumed initially very eccentric (e $\sim$ 0.1), which seems fairly unlikely the system, or alternately, if protoplanetary disk...
We present the discovery of KIC 9632895b, a 6.2 Earth-radius planet in low-eccentricity, 240.5-day orbit about an eclipsing binary. The binary itself consists 0.93 and 0.194 solar mass pair stars with orbital period 27.3 days. plane planet's is rapidly precessing, its inclination only becomes sufficiently aligned primary star latter portion Kepler data. Thus three transits are half light curve, but none conjunctions that occurred during first curve produced transits. precession ~103 years,...
We report the discovery of a new Kepler transiting circumbinary planet (CBP). This latest addition to still-small family CBPs defies current trend known short-period planets orbiting near stability limit binary stars. Unlike previous discoveries, revolving around eclipsing system Kepler-1647 has very long orbital period (~1100 days) and was at conjunction only twice during mission lifetime. Due singular configuration system, Kepler-1647b is not longest-period CBP time writing, but also one...
Of the nine confirmed transiting circumbinary planet systems, only Kepler-47 is known to contain more than one planet. b (the "inner planet") has an orbital period of 49.5 days and a radius about $3\,R_{\oplus}$. c "outer 303.2 $4.7\,R_{\oplus}$. Here we report discovery third planet, d "middle planet"), which 187.4 $7\,R_{\oplus}$. The presence middle allows us place much better constraints on masses all three planets, where $1\sigma$ ranges are less $26\,M_{\oplus}$, between...
We report the detection of first circumbinary planet found by TESS. The target, a known eclipsing binary, was observed in sectors 1 through 12 at 30-minute cadence and 4 two-minute cadence. It consists two stars with masses 1.1 MSun 0.3 on slightly eccentric (0.16), 14.6-day orbit, producing prominent primary eclipses shallow secondary eclipses. has radius ~6.9 REarth to make three transits across star roughly equal depths (~0.2%) but different durations -- common signature transiting...
All four giant planets in the Solar system possess irregular satellites, characterized by large, highly eccentric and/or inclined orbits that are distinct from nearly circular, uninclined of regular satellites. This difference can be traced directly to different modes formation. Whereas satellites grew accretion within circumplanetary disks were captured initially heliocentric at an early epoch. Recently, powerful survey observations have greatly increased number known permitting a fresh...
Recently, a number of planets orbiting binary stars have been discovered by the Kepler space telescope. In few systems reside close to dynamical stability limit. Due difficulty forming in such orbits, it is believed that they formed further out disk and migrated their present locations. Our goal construct more realistic models planet migration circumbinary disks, determine final position these planets. our work, we focus on system Kepler-38. The evolution studied using two-dimensional...
In this work we propose a new orbital architecture for the two proposed circumbinary planets around polar eclipsing binary HU Aquarii. We base two-planet, light-travel time model on result of Monte Carlo simulation driving least-squares Levenberg–Marquardt minimization algorithm observed eclipse egress times. Our best-fitting with resulted in high final eccentricities companions leading to an unstable configuration. From large ensemble initial guesses, examined distribution and semimajor...
In this work, we investigate the eclipse timing of polar binary HU Aquarii that has been observed for almost two decades. Recently, Qian et al. attributed large (O-C) deviations between ephemeris and observations to a compact system massive jovian companions. We improve Keplerian, kinematic model Light Travel Time (LTT) effect re-analyse whole currently available data set. add 60 new, yet unpublished, mostly precision light curves obtained using time high-resolution photo-polarimeter OPTIMA,...
The stability limit for circumbinary planets (CBPs) is not well defined and can depend on initial parameters defining either the planetary orbit or inner binary orbit. We expand work of Holman & Wiegert (1999, AJ 117, 621) to develop numerical tools quick, easy, accurate determination limit. results our simulations, as tools, are available community through $\texttt{Zenodo}$ $\texttt{GitHub}$, respectively. employ a grid interpolation method based $\sim$150 million full N-body simulations...
We report the first discovery of a transiting circumbinary planet detected from single sector TESS data. During Sector 21, TIC 172900988b transited primary star and then 5 days later it secondary star. The binary is itself eclipsing, with period P = 19.7 an eccentricity e 0.45. Archival data ASAS-SN, Evryscope, KELT, SuperWASP reveal prominent apsidal motion orbit, caused by dynamical interactions between planet. A comprehensive photodynamical analysis TESS, archival follow-up yields stellar...
We study the motions of small solids, ranging from micron-sized dust grains to 100 m objects, in vicinity a local density enhancement an isothermal gaseous solar nebula. Being interested possible application results formation planetesimals clumps and spiral arms circumstellar disk, we numerically integrate equations motion such solids their migrations for different values sizes masses also physical properties gas, as its temperature. show that, considering drag force it is within certain...
We study the motions of small solids, ranging from micron-sized dust grains to meter-sized objects, in vicinity local pressure enhancements a gaseous nebula. Integrating numerically, we show that as result combined effect gas drag and gradients, solids tend accumulate at locations where maximizes. The rate migration varies with their sizes densities also physical properties gas. results our numerical simulations indicate such migrations are most rapid for objects. applicability enhancement...
We present a study of the newly discovered main-belt comet P/2008 R1 (Garradd), an object with dynamical characteristics asteroid and physical comet. Photometry sets limit to effective radius nucleus at re< 0.7 km (red geometric albedo 0.05 assumed). The coma shows secular fading in our data caused by escape dust particles from near-nucleus environment. optical reflection spectrum is nearly neutral continuum devoid gaseous emission lines, which we derive cyanide (CN) radical production rate...
Precision radial velocities from Keck/HIRES reveal a Saturn-mass planet orbiting the nearby M4V star HIP 57050. The has minimum mass of 0.3 Jupiter-mass, an orbital period 41.4 days, and eccentricity 0.31. V-band photometry reveals clear stellar rotation signature host with 98 well separated velocity variations reinforcing Keplerian origin for observed variations. this corresponds to orbit in habitable zone 57050, expected planetary temperature approximately 230 K. metallicity [Fe/H] =...
We present observations and a dynamical analysis of the comet-like main-belt object, (596) Scheila. V-band photometry obtained on UT 2010 December 12 indicates that Scheila's dust cloud has scattering cross-section ~1.4 times larger than nucleus, corresponding to mass M_d~3x10^7 kg. V-R color measurements indicate both nucleus are redder Sun, with no significant differences between cloud's northern southern plumes. also undertake an ultimately unsuccessful search for CN emission, where we...
Binary and multiple systems constitute more than half of the total stellar population in Solar neighborhood (Kiseleva-Eggleton Eggleton 2001). Their frequent occurrence as well fact that 70 (Schneider et al. 2011) planets have already been discovered such configurations - most noteably telluric companion alpha Centauri B (Dumusque 2012) make them interesting targets search for habitable worlds. Recent studies (Eggl 2012b, Forgan shown, despite variations gravitational radiative environment,...
One of the most important subjects debate in formation solar system is origin Earth's water. Comets have long been considered as likely source delivery water to Earth. However, elemental and isotopic arguments suggest a very small contribution from these objects. Other sources also proposed, among which local adsorption vapor onto dust grains primordial nebula through planetesimals planetary embryos become more prominent. no sole provides satisfactory explanation for whole. In view that,...
It has been suggested that the long-lived residual radial velocity variations observed in precision measurements of primary γ Cephei (HR 8974, HD 222404, HIP 116727) are likely due to a Jupiter-like planet orbiting this star. In paper, dynamics is studied, and possibility existence terrestrial around its central star discussed. Simulations, which have carried out for different values eccentricity semimajor axis binary, as well orbital inclination planet, expand on previous studies system...
Recent radial velocity observations have indicated that Jovian-type planets can exist in moderately close binary star systems. Numerical simulations of the dynamical stability terrestrial-class such environments shown that, addition to their giant planets, these systems also harbor Earth-like objects. In this paper we study late stage terrestrial planet formation planetary systems, and present results bodies habitable zones. We consider a circumprimary disk Moon- Mars-sized objects...