The Experts below are selected from a list of 54 Experts worldwide ranked by ideXlab platform
Matthew J Payne - One of the best experts on this subject based on the ideXlab platform.
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an empirically derived three dimensional laplace resonance in the gliese 876 planetary system
Monthly Notices of the Royal Astronomical Society, 2016Co-Authors: Benjamin E Nelson, Eric B Ford, Jason T Wright, Matthew J Payne, Paul Robertson, Seth Pritchard, Katherine M Deck, Howard IsaacsonAbstract:We report constraints on the three-dimensional orbital architecture for all four planets known to orbit the nearby M dwarf Gliese 876 based solely on Doppler measurements and demanding long-term orbital stability. Our data set incorporates publicly available radial velocities taken with the ELODIE and CORALIE spectrographs, High Accuracy Radial velocity Planet Searcher (HARPS), and Keck HIgh Resolution Echelle Spectrometer (HIRES) as well as previously unpublished HIRES velocities. We first quantitatively assess the validity of the planets thought to orbit GJ 876 by computing the Bayes factors for a variety of different coplanar models using an importance sampling algorithm. We find that a four-planet model is preferred over a three-planet model. Next, we apply a Newtonian Markov chain Monte Carlo algorithm to perform a Bayesian analysis of the planet masses and orbits using an N-body model in three-dimensional space. Based on the radial velocities alone, we find that a 99 per cent credible interval provides upper limits on the mutual inclinations for the three resonant planets (Φ_(cb) <6∘.20 for the cc and bb pair and Φ_(be) < 28∘.5 for the b and e pair). Subsequent dynamical integrations of our Posterior Sample find that the GJ 876 planets must be roughly coplanar (Φ_(cb) < 2∘.60 and Φ_(be) <7∘.87), suggesting that the amount of planet–planet scattering in the system has been low. We investigate the distribution of the respective resonant arguments of each planet pair and find that at least one argument for each planet pair and the Laplace argument librate. The libration amplitudes in our three-dimensional orbital model support the idea of the outer three planets having undergone significant past disc migration.
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the 55 cancri planetary system fully self consistent n body constraints and a dynamical analysis
Monthly Notices of the Royal Astronomical Society, 2014Co-Authors: Benjamin E Nelson, Eric B Ford, Jason T Wright, Debra A Fischer, Kaspar Von Braun, Andrew W Howard, Matthew J PayneAbstract:We present an updated study of the planets known to orbit 55 Cancri A using 1 418 high-precision radial velocity observations from four observatories (Lick, Keck, Hobby-Eberly Telescope, Harlan J. Smith Telescope) and transit time/durations for the inner-most planet, 55 Cancri ‘e’ (Winn et al. 2011). We provide the first Posterior Sample for the masses and orbital parameters based on self-consistent N-body orbital solutions for the 55 Cancri planets, all of which are dynamically stable (for at least 10^8 yr). We apply a GPU version of Radial velocity Using N-body Differential evolution Markov Chain Monte Carlo (RUN DMC; Nelson, Ford & Payne) to perform a Bayesian analysis of the radial velocity and transit observations. Each of the planets in this remarkable system has unique characteristics. Our investigation of high-cadence radial velocities and priors based on space-based photometry yields an updated mass estimate for planet ‘e’ (8.09 ± 0.26 M⊕), which affects its density (5.51±^(1.32)_(1.00)g cm^(−3)) and inferred bulk composition. Dynamical stability dictates that the orbital plane of planet ‘e’ must be aligned to within 60° of the orbital plane of the outer planets (which we assume to be coplanar). The mutual interactions between the planets ‘b’ and ‘c’ may develop an apsidal lock about 180°. We find 36–45 per cent of all our model systems librate about the anti-aligned configuration with an amplitude of 51∘±^(6∘)_(10∘). Other cases showed short-term perturbations in the libration of ϖb − ϖc, circulation, and nodding, but we find the planets are not in a 3:1 mean-motion resonance. A revised orbital period and eccentricity for planet ‘d’ pushes it further towards the closest known Jupiter analogue in the exoplanet population.
Benjamin E Nelson - One of the best experts on this subject based on the ideXlab platform.
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an empirically derived three dimensional laplace resonance in the gliese 876 planetary system
Monthly Notices of the Royal Astronomical Society, 2016Co-Authors: Benjamin E Nelson, Eric B Ford, Jason T Wright, Matthew J Payne, Paul Robertson, Seth Pritchard, Katherine M Deck, Howard IsaacsonAbstract:We report constraints on the three-dimensional orbital architecture for all four planets known to orbit the nearby M dwarf Gliese 876 based solely on Doppler measurements and demanding long-term orbital stability. Our data set incorporates publicly available radial velocities taken with the ELODIE and CORALIE spectrographs, High Accuracy Radial velocity Planet Searcher (HARPS), and Keck HIgh Resolution Echelle Spectrometer (HIRES) as well as previously unpublished HIRES velocities. We first quantitatively assess the validity of the planets thought to orbit GJ 876 by computing the Bayes factors for a variety of different coplanar models using an importance sampling algorithm. We find that a four-planet model is preferred over a three-planet model. Next, we apply a Newtonian Markov chain Monte Carlo algorithm to perform a Bayesian analysis of the planet masses and orbits using an N-body model in three-dimensional space. Based on the radial velocities alone, we find that a 99 per cent credible interval provides upper limits on the mutual inclinations for the three resonant planets (Φ_(cb) <6∘.20 for the cc and bb pair and Φ_(be) < 28∘.5 for the b and e pair). Subsequent dynamical integrations of our Posterior Sample find that the GJ 876 planets must be roughly coplanar (Φ_(cb) < 2∘.60 and Φ_(be) <7∘.87), suggesting that the amount of planet–planet scattering in the system has been low. We investigate the distribution of the respective resonant arguments of each planet pair and find that at least one argument for each planet pair and the Laplace argument librate. The libration amplitudes in our three-dimensional orbital model support the idea of the outer three planets having undergone significant past disc migration.
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the 55 cancri planetary system fully self consistent n body constraints and a dynamical analysis
Monthly Notices of the Royal Astronomical Society, 2014Co-Authors: Benjamin E Nelson, Eric B Ford, Jason T Wright, Debra A Fischer, Kaspar Von Braun, Andrew W Howard, Matthew J PayneAbstract:We present an updated study of the planets known to orbit 55 Cancri A using 1 418 high-precision radial velocity observations from four observatories (Lick, Keck, Hobby-Eberly Telescope, Harlan J. Smith Telescope) and transit time/durations for the inner-most planet, 55 Cancri ‘e’ (Winn et al. 2011). We provide the first Posterior Sample for the masses and orbital parameters based on self-consistent N-body orbital solutions for the 55 Cancri planets, all of which are dynamically stable (for at least 10^8 yr). We apply a GPU version of Radial velocity Using N-body Differential evolution Markov Chain Monte Carlo (RUN DMC; Nelson, Ford & Payne) to perform a Bayesian analysis of the radial velocity and transit observations. Each of the planets in this remarkable system has unique characteristics. Our investigation of high-cadence radial velocities and priors based on space-based photometry yields an updated mass estimate for planet ‘e’ (8.09 ± 0.26 M⊕), which affects its density (5.51±^(1.32)_(1.00)g cm^(−3)) and inferred bulk composition. Dynamical stability dictates that the orbital plane of planet ‘e’ must be aligned to within 60° of the orbital plane of the outer planets (which we assume to be coplanar). The mutual interactions between the planets ‘b’ and ‘c’ may develop an apsidal lock about 180°. We find 36–45 per cent of all our model systems librate about the anti-aligned configuration with an amplitude of 51∘±^(6∘)_(10∘). Other cases showed short-term perturbations in the libration of ϖb − ϖc, circulation, and nodding, but we find the planets are not in a 3:1 mean-motion resonance. A revised orbital period and eccentricity for planet ‘d’ pushes it further towards the closest known Jupiter analogue in the exoplanet population.
Eric B Ford - One of the best experts on this subject based on the ideXlab platform.
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an empirically derived three dimensional laplace resonance in the gliese 876 planetary system
Monthly Notices of the Royal Astronomical Society, 2016Co-Authors: Benjamin E Nelson, Eric B Ford, Jason T Wright, Matthew J Payne, Paul Robertson, Seth Pritchard, Katherine M Deck, Howard IsaacsonAbstract:We report constraints on the three-dimensional orbital architecture for all four planets known to orbit the nearby M dwarf Gliese 876 based solely on Doppler measurements and demanding long-term orbital stability. Our data set incorporates publicly available radial velocities taken with the ELODIE and CORALIE spectrographs, High Accuracy Radial velocity Planet Searcher (HARPS), and Keck HIgh Resolution Echelle Spectrometer (HIRES) as well as previously unpublished HIRES velocities. We first quantitatively assess the validity of the planets thought to orbit GJ 876 by computing the Bayes factors for a variety of different coplanar models using an importance sampling algorithm. We find that a four-planet model is preferred over a three-planet model. Next, we apply a Newtonian Markov chain Monte Carlo algorithm to perform a Bayesian analysis of the planet masses and orbits using an N-body model in three-dimensional space. Based on the radial velocities alone, we find that a 99 per cent credible interval provides upper limits on the mutual inclinations for the three resonant planets (Φ_(cb) <6∘.20 for the cc and bb pair and Φ_(be) < 28∘.5 for the b and e pair). Subsequent dynamical integrations of our Posterior Sample find that the GJ 876 planets must be roughly coplanar (Φ_(cb) < 2∘.60 and Φ_(be) <7∘.87), suggesting that the amount of planet–planet scattering in the system has been low. We investigate the distribution of the respective resonant arguments of each planet pair and find that at least one argument for each planet pair and the Laplace argument librate. The libration amplitudes in our three-dimensional orbital model support the idea of the outer three planets having undergone significant past disc migration.
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the 55 cancri planetary system fully self consistent n body constraints and a dynamical analysis
Monthly Notices of the Royal Astronomical Society, 2014Co-Authors: Benjamin E Nelson, Eric B Ford, Jason T Wright, Debra A Fischer, Kaspar Von Braun, Andrew W Howard, Matthew J PayneAbstract:We present an updated study of the planets known to orbit 55 Cancri A using 1 418 high-precision radial velocity observations from four observatories (Lick, Keck, Hobby-Eberly Telescope, Harlan J. Smith Telescope) and transit time/durations for the inner-most planet, 55 Cancri ‘e’ (Winn et al. 2011). We provide the first Posterior Sample for the masses and orbital parameters based on self-consistent N-body orbital solutions for the 55 Cancri planets, all of which are dynamically stable (for at least 10^8 yr). We apply a GPU version of Radial velocity Using N-body Differential evolution Markov Chain Monte Carlo (RUN DMC; Nelson, Ford & Payne) to perform a Bayesian analysis of the radial velocity and transit observations. Each of the planets in this remarkable system has unique characteristics. Our investigation of high-cadence radial velocities and priors based on space-based photometry yields an updated mass estimate for planet ‘e’ (8.09 ± 0.26 M⊕), which affects its density (5.51±^(1.32)_(1.00)g cm^(−3)) and inferred bulk composition. Dynamical stability dictates that the orbital plane of planet ‘e’ must be aligned to within 60° of the orbital plane of the outer planets (which we assume to be coplanar). The mutual interactions between the planets ‘b’ and ‘c’ may develop an apsidal lock about 180°. We find 36–45 per cent of all our model systems librate about the anti-aligned configuration with an amplitude of 51∘±^(6∘)_(10∘). Other cases showed short-term perturbations in the libration of ϖb − ϖc, circulation, and nodding, but we find the planets are not in a 3:1 mean-motion resonance. A revised orbital period and eccentricity for planet ‘d’ pushes it further towards the closest known Jupiter analogue in the exoplanet population.
Jason T Wright - One of the best experts on this subject based on the ideXlab platform.
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an empirically derived three dimensional laplace resonance in the gliese 876 planetary system
Monthly Notices of the Royal Astronomical Society, 2016Co-Authors: Benjamin E Nelson, Eric B Ford, Jason T Wright, Matthew J Payne, Paul Robertson, Seth Pritchard, Katherine M Deck, Howard IsaacsonAbstract:We report constraints on the three-dimensional orbital architecture for all four planets known to orbit the nearby M dwarf Gliese 876 based solely on Doppler measurements and demanding long-term orbital stability. Our data set incorporates publicly available radial velocities taken with the ELODIE and CORALIE spectrographs, High Accuracy Radial velocity Planet Searcher (HARPS), and Keck HIgh Resolution Echelle Spectrometer (HIRES) as well as previously unpublished HIRES velocities. We first quantitatively assess the validity of the planets thought to orbit GJ 876 by computing the Bayes factors for a variety of different coplanar models using an importance sampling algorithm. We find that a four-planet model is preferred over a three-planet model. Next, we apply a Newtonian Markov chain Monte Carlo algorithm to perform a Bayesian analysis of the planet masses and orbits using an N-body model in three-dimensional space. Based on the radial velocities alone, we find that a 99 per cent credible interval provides upper limits on the mutual inclinations for the three resonant planets (Φ_(cb) <6∘.20 for the cc and bb pair and Φ_(be) < 28∘.5 for the b and e pair). Subsequent dynamical integrations of our Posterior Sample find that the GJ 876 planets must be roughly coplanar (Φ_(cb) < 2∘.60 and Φ_(be) <7∘.87), suggesting that the amount of planet–planet scattering in the system has been low. We investigate the distribution of the respective resonant arguments of each planet pair and find that at least one argument for each planet pair and the Laplace argument librate. The libration amplitudes in our three-dimensional orbital model support the idea of the outer three planets having undergone significant past disc migration.
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the 55 cancri planetary system fully self consistent n body constraints and a dynamical analysis
Monthly Notices of the Royal Astronomical Society, 2014Co-Authors: Benjamin E Nelson, Eric B Ford, Jason T Wright, Debra A Fischer, Kaspar Von Braun, Andrew W Howard, Matthew J PayneAbstract:We present an updated study of the planets known to orbit 55 Cancri A using 1 418 high-precision radial velocity observations from four observatories (Lick, Keck, Hobby-Eberly Telescope, Harlan J. Smith Telescope) and transit time/durations for the inner-most planet, 55 Cancri ‘e’ (Winn et al. 2011). We provide the first Posterior Sample for the masses and orbital parameters based on self-consistent N-body orbital solutions for the 55 Cancri planets, all of which are dynamically stable (for at least 10^8 yr). We apply a GPU version of Radial velocity Using N-body Differential evolution Markov Chain Monte Carlo (RUN DMC; Nelson, Ford & Payne) to perform a Bayesian analysis of the radial velocity and transit observations. Each of the planets in this remarkable system has unique characteristics. Our investigation of high-cadence radial velocities and priors based on space-based photometry yields an updated mass estimate for planet ‘e’ (8.09 ± 0.26 M⊕), which affects its density (5.51±^(1.32)_(1.00)g cm^(−3)) and inferred bulk composition. Dynamical stability dictates that the orbital plane of planet ‘e’ must be aligned to within 60° of the orbital plane of the outer planets (which we assume to be coplanar). The mutual interactions between the planets ‘b’ and ‘c’ may develop an apsidal lock about 180°. We find 36–45 per cent of all our model systems librate about the anti-aligned configuration with an amplitude of 51∘±^(6∘)_(10∘). Other cases showed short-term perturbations in the libration of ϖb − ϖc, circulation, and nodding, but we find the planets are not in a 3:1 mean-motion resonance. A revised orbital period and eccentricity for planet ‘d’ pushes it further towards the closest known Jupiter analogue in the exoplanet population.
Howard Isaacson - One of the best experts on this subject based on the ideXlab platform.
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an empirically derived three dimensional laplace resonance in the gliese 876 planetary system
Monthly Notices of the Royal Astronomical Society, 2016Co-Authors: Benjamin E Nelson, Eric B Ford, Jason T Wright, Matthew J Payne, Paul Robertson, Seth Pritchard, Katherine M Deck, Howard IsaacsonAbstract:We report constraints on the three-dimensional orbital architecture for all four planets known to orbit the nearby M dwarf Gliese 876 based solely on Doppler measurements and demanding long-term orbital stability. Our data set incorporates publicly available radial velocities taken with the ELODIE and CORALIE spectrographs, High Accuracy Radial velocity Planet Searcher (HARPS), and Keck HIgh Resolution Echelle Spectrometer (HIRES) as well as previously unpublished HIRES velocities. We first quantitatively assess the validity of the planets thought to orbit GJ 876 by computing the Bayes factors for a variety of different coplanar models using an importance sampling algorithm. We find that a four-planet model is preferred over a three-planet model. Next, we apply a Newtonian Markov chain Monte Carlo algorithm to perform a Bayesian analysis of the planet masses and orbits using an N-body model in three-dimensional space. Based on the radial velocities alone, we find that a 99 per cent credible interval provides upper limits on the mutual inclinations for the three resonant planets (Φ_(cb) <6∘.20 for the cc and bb pair and Φ_(be) < 28∘.5 for the b and e pair). Subsequent dynamical integrations of our Posterior Sample find that the GJ 876 planets must be roughly coplanar (Φ_(cb) < 2∘.60 and Φ_(be) <7∘.87), suggesting that the amount of planet–planet scattering in the system has been low. We investigate the distribution of the respective resonant arguments of each planet pair and find that at least one argument for each planet pair and the Laplace argument librate. The libration amplitudes in our three-dimensional orbital model support the idea of the outer three planets having undergone significant past disc migration.
