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M Mayor - One of the best experts on this subject based on the ideXlab platform.
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an extrasolar Planetary system with three neptune mass Planets
Nature, 2006Co-Authors: Christophe Lovis, Jacques Laskar, Yann Alibert, Christoph Mordasini, M Mayor, F Bouchy, F. Pepe, W. Benz, A.c.m. Correia, D QuelozAbstract:Over the past two years, the search for low-mass extrasolar Planets has led to the detection of seven so-called ‘hot Neptunes’ or ‘super-Earths’ around Sun-like stars. These Planets have masses 5–20 times larger than the Earth and are mainly found on close-in orbits with periods of 2–15 days. Here we report a system of three Neptune-mass Planets with periods of 8.67, 31.6 and 197 days, orbiting the nearby star HD 69830. This star was already known to show an infrared excess possibly caused by an asteroid belt within 1 au (the Sun–Earth distance). Simulations show that the system is in a dynamically stable configuration. Theoretical calculations favour a mainly rocky composition for both inner Planets, while the Outer Planet probably has a significant gaseous envelope surrounding its rocky/icy core; the Outer Planet orbits within the habitable zone of this star. As the techniques used to search for extrasolar Planets have been refined, more and more have been discovered (over 170), and they get smaller. In recent years seven ‘hot Neptunes’ or ‘super-Earths’ have been detected. These have masses 5–20 times larger than the Earth and are in close-in orbits (periods of 2–15 days) around Sun-like stars. Now the first multiple system of three Neptune-mass Planets has been found, with periods of 8.67, 31.6 and (in the ‘habitable’ zone) 197 days. They are orbiting the nearby star HD 69830. Theoretical calculations favour a mainly rocky composition for both inner Planets. The Outer Planet probably has a significant gaseous envelope surrounding a rocky/icy core: it is the first Neptune-mass object detected inside the habitable zone of a Sun-like star. Simulations show that the system of three Neptune-mass Planets is in a dynamically stable configuration, with theoretical calculations favouring a mainly rocky composition for both inner Planets, but a significant gaseous envelope surrounding a rocky/icy core for the Outer Planet.
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detection of a neptune mass Planet in the ρ 1 cancri system using the hobby eberly telescope
The Astrophysical Journal, 2004Co-Authors: Barbara E Mcarthur, Geoffrey W Marcy, Debra A Fischer, William D Cochran, Michael Endl, Fritz G Benedict, Paul R Butler, D Naef, M MayorAbstract:We report the detection of the lowest mass extrasolar Planet yet found around a Sun-like star—a Planet with an M sin i of only 14.21 ± 2.91 M⊕ in an extremely short period orbit (P = 2.808 days) around ρ1 Cancri, a Planetary system that already has three known Planets. Velocities taken from late 2003-2004 at McDonald Observatory with the Hobby-Eberly Telescope revealed this inner Planet at 0.04 AU. We estimate an inclination of the Outer Planet ρ1 Cancri d, based on Hubble Space Telescope Fine Guidance Sensor measurements that suggest an inner Planet of only 17.7 ± 5.57 M⊕, if coplanarity is assumed for the system.
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detection of a neptune mass Planet in the rho 1 cancri system using the hobby eberly telescope
arXiv: Astrophysics, 2004Co-Authors: Barbara E Mcarthur, M Mayor, Geoffrey W Marcy, Debra A Fischer, William D Cochran, Michael Endl, Fritz G Benedict, Paul R Butler, D Naef, D QuelozAbstract:We report the detection of the lowest mass extra-solar Planet yet found around a Sun-like star - a Planet with an \msini of only 14.21 $\pm$ 2.91 Earth masses in an extremely short period orbit (P=2.808 days) around $\rho^{1}$ Cancri, a Planetary system which already has three known Planets. Velocities taken from late 2003-2004 at McDonald Observatory with the Hobby-Eberly Telescope (HET) revealed this inner Planet at 0.04 AU. We estimate an inclination of the Outer Planet $\rho^{1}$ Cancri d, based upon {\it Hubble Space Telescope} Fine Guidance Sensor (FGS) measurements. This inclination suggests an inner Planet of only 17.7 $\pm$ 5.57 Earth masses, if coplanarity is assumed for the system.
Michael Cupples - One of the best experts on this subject based on the ideXlab platform.
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low thrust trajectory optimization procedure for gravity assist Outer Planet missions
Journal of Spacecraft and Rockets, 2006Co-Authors: Byoungsam Woo, Victoria L Coverstone, Michael CupplesAbstract:A hybrid trajectory optimization procedure for a class of solar-electric-propulsion, gravity-assist, Outer-Planet missions is presented. The parameter space of a target mission is often nonconvex and a calculus-of-variations-based optimization algorithm suffers difficulties efficiently exploring this space. A hybrid procedure using a genetic algorithm to drive a calculus-of-variations program is developed to automate searching over a reduced parameter space. Employing the hybrid procedure, the delivered mass profiles of a Uranus and Pluto mission are generated more quickly than by using the calculus-of-variations optimization algorithm alone.
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trajectory and system analysis for Outer Planet solar electric propulsion missions
Journal of Spacecraft and Rockets, 2005Co-Authors: Byoungsam Woo, Victoria L Coverstone, John W Hartmann, Michael CupplesAbstract:Outer-Planet mission and systems analyses are performed using three next generation solar-electric ion thruster models. The impact of variations in thruster model, flight time, launch vehicle, propulsion and power systems characteristics is investigated. All presented trajectories have a single Venus gravity assist and maximize the delivered mass to Saturn or Neptune. The effect of revolution ratio - the ratio of Venusian orbital period to the flight time between launch and flyby dates - is also discussed.
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effects of gravity assist timing on Outer Planet missions using solar electric propulsion
Collection of Technical Papers - AIAA AAS Astrodynamics Specialist Conference, 2004Co-Authors: Byoungsam Woo, Victoria L Coverstone, Michael CupplesAbstract:Missions to the Outer Planets for spacecraft with a solar-electric propulsion system (SEPS) and that utilize a single Venus gravity assist are investigated. The trajectories maximize the delivered mass to the target Planet for a range of flight times. A comparison of the trajectory characteristics (delivered mass, launch energy and onboard propulsive energy) is made for various Venus gravity assist opportunities. Methods to estimate the delivered mass to the Outer Planets are developed.
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Outer Planet mission analysis using solar electric ion propulsion
Spaceflight Mechanics 2003: Proceedings of the AAS AIAA Space Flight Mechanics Meeting, 2003Co-Authors: Byoungsam Woo, Victoria L Coverstone, John W Hartmann, Michael CupplesAbstract:Outer-Planet mission analysis was performed using three next generation solar-electric ion thruster models. Optimal trajectories are presented that maximize the delivered mass to the designated Outer Planet. Trajectories to Saturn and Neptune with a single Venus gravity assist are investigated. For each thruster model, the delivered mass versus flight time curve was generated to obtain thruster model performance. The effects of power to the thrusters and resonance ratio of Venutian orbital periods to spacecraft period were also studied. Multiple locally optimal trajectories to Saturn and Neptune have been discovered in different regions of the parameter search space. The characteristics of each trajectory are noted.
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factors influencing solar electric propulsion vehicle payload delivery for Outer Planet missions
Spaceflight Mechanics 2003: Proceedings of the AAS AIAA Space Flight Mechanics Meeting, 2003Co-Authors: Michael Cupples, Shaun E Green, Victoria L CoverstoneAbstract:Systems analyses were performed for missions utilizing solar electric propulsion systems to deliver payloads to Outer-Planet destinations. A range of mission and systems factors and their affect on the delivery capability of the solar electric propulsion system was examined. The effect of varying the destination, the trip time, the launch vehicle, and gravity-assist boundary conditions was investigated. In addition, the affects of selecting propulsion system and power systems characteristics (including primary array power variation, number of thrusters, thruster throttling mode, and thruster Isp) on delivered payload was examined.
William D Cochran - One of the best experts on this subject based on the ideXlab platform.
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a mini neptune and a venus zone Planet in the radius valley orbiting the nearby m2 dwarf toi 1266 validation with the habitable zone Planet finder
arXiv: Earth and Planetary Astrophysics, 2020Co-Authors: Gudmundur Stefansson, Ravi Kumar Kopparapu, Andrea S J Lin, Suvrath Mahadevan, Caleb Canas, Shubham Kanodia, J P Ninan, William D Cochran, Michael Endl, Leslie HebbAbstract:We report on the validation of two Planets orbiting the nearby (36pc) M2 dwarf TOI-1266 observed by the TESS mission. The inner Planet is sub-Neptune-sized ($R=2.46 \pm 0.08 R_\oplus$) with an orbital period of 10.9 days. The Outer Planet has a radius of $1.67_{-0.11}^{+0.09} R_\oplus$ and resides in the exoPlanet Radius Valley---the transition region between rocky and gaseous Planets. With an orbital period of 18.8 days, the Outer Planet receives an insolation flux of 2.4 times that of Earth, similar to the insolation of Venus. Using precision near-infrared radial velocities with the Habitable-zone Planet Finder Spectrograph, we place upper mass limits of $15.9 M_\oplus$ and $6.4 M_\oplus$ at 95% confidence for the inner and Outer Planet, respectively. A more precise mass constraint of Planet c, achievable with current RV instruments given the host star brightness (V=12.9, J=9.7), will yield further insights into the dominant processes sculpting the exoPlanet Radius Valley.
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detection of a neptune mass Planet in the ρ 1 cancri system using the hobby eberly telescope
The Astrophysical Journal, 2004Co-Authors: Barbara E Mcarthur, Geoffrey W Marcy, Debra A Fischer, William D Cochran, Michael Endl, Fritz G Benedict, Paul R Butler, D Naef, M MayorAbstract:We report the detection of the lowest mass extrasolar Planet yet found around a Sun-like star—a Planet with an M sin i of only 14.21 ± 2.91 M⊕ in an extremely short period orbit (P = 2.808 days) around ρ1 Cancri, a Planetary system that already has three known Planets. Velocities taken from late 2003-2004 at McDonald Observatory with the Hobby-Eberly Telescope revealed this inner Planet at 0.04 AU. We estimate an inclination of the Outer Planet ρ1 Cancri d, based on Hubble Space Telescope Fine Guidance Sensor measurements that suggest an inner Planet of only 17.7 ± 5.57 M⊕, if coplanarity is assumed for the system.
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detection of a neptune mass Planet in the rho 1 cancri system using the hobby eberly telescope
arXiv: Astrophysics, 2004Co-Authors: Barbara E Mcarthur, M Mayor, Geoffrey W Marcy, Debra A Fischer, William D Cochran, Michael Endl, Fritz G Benedict, Paul R Butler, D Naef, D QuelozAbstract:We report the detection of the lowest mass extra-solar Planet yet found around a Sun-like star - a Planet with an \msini of only 14.21 $\pm$ 2.91 Earth masses in an extremely short period orbit (P=2.808 days) around $\rho^{1}$ Cancri, a Planetary system which already has three known Planets. Velocities taken from late 2003-2004 at McDonald Observatory with the Hobby-Eberly Telescope (HET) revealed this inner Planet at 0.04 AU. We estimate an inclination of the Outer Planet $\rho^{1}$ Cancri d, based upon {\it Hubble Space Telescope} Fine Guidance Sensor (FGS) measurements. This inclination suggests an inner Planet of only 17.7 $\pm$ 5.57 Earth masses, if coplanarity is assumed for the system.
Michael Endl - One of the best experts on this subject based on the ideXlab platform.
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a mini neptune and a venus zone Planet in the radius valley orbiting the nearby m2 dwarf toi 1266 validation with the habitable zone Planet finder
arXiv: Earth and Planetary Astrophysics, 2020Co-Authors: Gudmundur Stefansson, Ravi Kumar Kopparapu, Andrea S J Lin, Suvrath Mahadevan, Caleb Canas, Shubham Kanodia, J P Ninan, William D Cochran, Michael Endl, Leslie HebbAbstract:We report on the validation of two Planets orbiting the nearby (36pc) M2 dwarf TOI-1266 observed by the TESS mission. The inner Planet is sub-Neptune-sized ($R=2.46 \pm 0.08 R_\oplus$) with an orbital period of 10.9 days. The Outer Planet has a radius of $1.67_{-0.11}^{+0.09} R_\oplus$ and resides in the exoPlanet Radius Valley---the transition region between rocky and gaseous Planets. With an orbital period of 18.8 days, the Outer Planet receives an insolation flux of 2.4 times that of Earth, similar to the insolation of Venus. Using precision near-infrared radial velocities with the Habitable-zone Planet Finder Spectrograph, we place upper mass limits of $15.9 M_\oplus$ and $6.4 M_\oplus$ at 95% confidence for the inner and Outer Planet, respectively. A more precise mass constraint of Planet c, achievable with current RV instruments given the host star brightness (V=12.9, J=9.7), will yield further insights into the dominant processes sculpting the exoPlanet Radius Valley.
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detection of a neptune mass Planet in the ρ 1 cancri system using the hobby eberly telescope
The Astrophysical Journal, 2004Co-Authors: Barbara E Mcarthur, Geoffrey W Marcy, Debra A Fischer, William D Cochran, Michael Endl, Fritz G Benedict, Paul R Butler, D Naef, M MayorAbstract:We report the detection of the lowest mass extrasolar Planet yet found around a Sun-like star—a Planet with an M sin i of only 14.21 ± 2.91 M⊕ in an extremely short period orbit (P = 2.808 days) around ρ1 Cancri, a Planetary system that already has three known Planets. Velocities taken from late 2003-2004 at McDonald Observatory with the Hobby-Eberly Telescope revealed this inner Planet at 0.04 AU. We estimate an inclination of the Outer Planet ρ1 Cancri d, based on Hubble Space Telescope Fine Guidance Sensor measurements that suggest an inner Planet of only 17.7 ± 5.57 M⊕, if coplanarity is assumed for the system.
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detection of a neptune mass Planet in the rho 1 cancri system using the hobby eberly telescope
arXiv: Astrophysics, 2004Co-Authors: Barbara E Mcarthur, M Mayor, Geoffrey W Marcy, Debra A Fischer, William D Cochran, Michael Endl, Fritz G Benedict, Paul R Butler, D Naef, D QuelozAbstract:We report the detection of the lowest mass extra-solar Planet yet found around a Sun-like star - a Planet with an \msini of only 14.21 $\pm$ 2.91 Earth masses in an extremely short period orbit (P=2.808 days) around $\rho^{1}$ Cancri, a Planetary system which already has three known Planets. Velocities taken from late 2003-2004 at McDonald Observatory with the Hobby-Eberly Telescope (HET) revealed this inner Planet at 0.04 AU. We estimate an inclination of the Outer Planet $\rho^{1}$ Cancri d, based upon {\it Hubble Space Telescope} Fine Guidance Sensor (FGS) measurements. This inclination suggests an inner Planet of only 17.7 $\pm$ 5.57 Earth masses, if coplanarity is assumed for the system.
D Queloz - One of the best experts on this subject based on the ideXlab platform.
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an extrasolar Planetary system with three neptune mass Planets
Nature, 2006Co-Authors: Christophe Lovis, Jacques Laskar, Yann Alibert, Christoph Mordasini, M Mayor, F Bouchy, F. Pepe, W. Benz, A.c.m. Correia, D QuelozAbstract:Over the past two years, the search for low-mass extrasolar Planets has led to the detection of seven so-called ‘hot Neptunes’ or ‘super-Earths’ around Sun-like stars. These Planets have masses 5–20 times larger than the Earth and are mainly found on close-in orbits with periods of 2–15 days. Here we report a system of three Neptune-mass Planets with periods of 8.67, 31.6 and 197 days, orbiting the nearby star HD 69830. This star was already known to show an infrared excess possibly caused by an asteroid belt within 1 au (the Sun–Earth distance). Simulations show that the system is in a dynamically stable configuration. Theoretical calculations favour a mainly rocky composition for both inner Planets, while the Outer Planet probably has a significant gaseous envelope surrounding its rocky/icy core; the Outer Planet orbits within the habitable zone of this star. As the techniques used to search for extrasolar Planets have been refined, more and more have been discovered (over 170), and they get smaller. In recent years seven ‘hot Neptunes’ or ‘super-Earths’ have been detected. These have masses 5–20 times larger than the Earth and are in close-in orbits (periods of 2–15 days) around Sun-like stars. Now the first multiple system of three Neptune-mass Planets has been found, with periods of 8.67, 31.6 and (in the ‘habitable’ zone) 197 days. They are orbiting the nearby star HD 69830. Theoretical calculations favour a mainly rocky composition for both inner Planets. The Outer Planet probably has a significant gaseous envelope surrounding a rocky/icy core: it is the first Neptune-mass object detected inside the habitable zone of a Sun-like star. Simulations show that the system of three Neptune-mass Planets is in a dynamically stable configuration, with theoretical calculations favouring a mainly rocky composition for both inner Planets, but a significant gaseous envelope surrounding a rocky/icy core for the Outer Planet.
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detection of a neptune mass Planet in the rho 1 cancri system using the hobby eberly telescope
arXiv: Astrophysics, 2004Co-Authors: Barbara E Mcarthur, M Mayor, Geoffrey W Marcy, Debra A Fischer, William D Cochran, Michael Endl, Fritz G Benedict, Paul R Butler, D Naef, D QuelozAbstract:We report the detection of the lowest mass extra-solar Planet yet found around a Sun-like star - a Planet with an \msini of only 14.21 $\pm$ 2.91 Earth masses in an extremely short period orbit (P=2.808 days) around $\rho^{1}$ Cancri, a Planetary system which already has three known Planets. Velocities taken from late 2003-2004 at McDonald Observatory with the Hobby-Eberly Telescope (HET) revealed this inner Planet at 0.04 AU. We estimate an inclination of the Outer Planet $\rho^{1}$ Cancri d, based upon {\it Hubble Space Telescope} Fine Guidance Sensor (FGS) measurements. This inclination suggests an inner Planet of only 17.7 $\pm$ 5.57 Earth masses, if coplanarity is assumed for the system.
