The Experts below are selected from a list of 46323 Experts worldwide ranked by ideXlab platform
Scott J. Kenyon - One of the best experts on this subject based on the ideXlab platform.
-
terrestrial Planet Formation dynamical shake up and the low mass of mars
The Astronomical Journal, 2017Co-Authors: Benjamin C. Bromley, Scott J. KenyonAbstract:We consider a dynamical shake-up model to explain the low mass of Mars and the lack of Planets in the asteroid belt. In our scenario, a secular resonance with Jupiter sweeps through the inner solar system as the solar nebula depletes, pitting resonant excitation against collisional damping in the Sun's protoPlanetary disk. We report the outcome of extensive numerical calculations of Planet Formation from Planetesimals in the terrestrial zone, with and without dynamical shake-up. If the Sun's gas disk within the terrestrial zone depletes in roughly a million years, then the sweeping resonance inhibits Planet Formation in the asteroid belt and substantially limits the size of Mars. This phenomenon likely occurs around other stars with long-period massive Planets, suggesting that asteroid belt analogs are common.
-
the last gasp of gas giant Planet Formation a spitzer study of the 5 myr old cluster ngc 2362
The Astrophysical Journal, 2009Co-Authors: Thayne Currie, Peter Plavchan, Charles J. Lada, Jonathan Irwin, Thomas Robitaille, Scott J. KenyonAbstract:Expanding upon the Infrared Array Camera (IRAC) survey from Dahm & Hillenbrand, we describe Spitzer IRAC and Multiband Imaging Photometer for Spitzer observations of the populous, 5 Myr old open cluster NGC 2362. We analyze the mid-IR colors of cluster members and compared their spectral energy distributions (SEDs) to star+circumstellar disk models to constrain the disk morphologies and evolutionary states. Early/intermediate-type confirmed/candidate cluster members either have photospheric mid-IR emission or weak, optically thin IR excess emission at λ ≥ 24 μm consistent with debris disks. Few late-type, solar/subsolar-mass stars have primordial disks. The disk population around late-type stars is dominated by disks with inner holes (canonical "transition disks") and "homologously depleted" disks. Both types of disks represent an intermediate stage between primordial disks and debris disks. Thus, in agreement with previous results, we find that multiple paths for the primordial-to-debris disk transition exist. Because these "evolved primordial disks" greatly outnumber primordial disks, our results undermine standard arguments in favor of a ≾10^5 yr timescale for the transition based on data from Taurus-Auriga. Because the typical transition timescale is far longer than 10^5 yr, these data also appear to rule out standard ultraviolet photoevaporation scenarios as the primary mechanism to explain the transition. Combining our data with other Spitzer surveys, we investigate the evolution of debris disks around high/intermediate-mass stars and investigate timescales for giant Planet Formation. Consistent with Currie et al., the luminosity of 24 μm emission in debris disks due to Planet Formation peaks at ≈10-20 Myr. If the gas and dust in disks evolve on similar timescales, the Formation timescale for gas giant Planets surrounding early-type, high/intermediate-mass (≾1.4 M_⊙ ) stars is likely 1-5 Myr. Most solar/subsolar-mass stars detected by Spitzer have SEDs that indicate their disks may be actively leaving the primordial disk phase. Thus, gas giant Planet Formation may also occur by ~5 Myr around solar/subsolar-mass stars as well.
-
The Last Gasp of Gas Giant Planet Formation: A Spitzer Study of the 5 Myr-old Cluster NGC 2362
The Astrophysical Journal, 2009Co-Authors: Thayne Currie, Peter Plavchan, Charles J. Lada, Thomas P. Robitaille, Jonathan Irwin, Scott J. KenyonAbstract:(Abridged) We describe Spitzer IRAC and MIPS observations of the populous, 5 Myr-old open cluster NGC 2362. Early/intermediate-type confirmed/candidate cluster members either have photospheric mid-IR emission or weak, optically-thin infrared excess emission at < 24 microns consistent with debris disks. Few late-type, solar/subsolar-mass stars have primordial disks. The disk population around late-type stars is dominated by disks with inner holes (canonical 'transition disks') and 'homologously depleted' disks. Both types of disks represent an intermediate stage between primordial disks and debris disks. Thus, we find that multiple paths for the primordial-to-debris disk transition exist. Our results undermine standard arguments in favor of a ~ 0.01 Myr year timescale for the transition based on data from Taurus-Auriga and rule out standard UV photoevaporation scenarios as the primary mechanism to explain the transition. Combining our data with other Spitzer surveys, we investigate the evolution of debris disks around high/intermediate-mass stars and investigate timescales for giant Planet Formation. If the gas and dust in disks evolve on similar timescales, the Formation timescale for gas giant Planets surrounding early-type, high/intermediate-mass stars is likely 1--5 Myr. Most solar/subsolar-mass stars detected by Spitzer have SEDs that indicate their disks may be actively leaving the primordial disk phase. Thus, gas giant Planet Formation may also occur by 5 Myr around solar/subsolar-mass stars as well.
-
terrestrial Planet Formation i the transition from oligarchic growth to chaotic growth
The Astronomical Journal, 2006Co-Authors: Scott J. Kenyon, Benjamin C. BromleyAbstract:We use a hybrid, multiannulus, n-body-coagulation code to investigate the growth of kilometer-sized Planetesimals at 0.4-2 AU around a solar-type star. After a short runaway growth phase, protoPlanets with masses of ~1026 g and larger form throughout the grid. When (1) the mass in these oligarchs is roughly comparable to the mass in Planetesimals and (2) the surface density in oligarchs exceeds 2-3 g cm-2 at 1 AU, strong dynamical interactions among oligarchs produce a high merger rate, which leads to the Formation of several terrestrial Planets. In disks with lower surface density, milder interactions produce several lower-mass Planets. In all disks, the Planet Formation timescale is ~10-100 Myr, similar to estimates derived from the cratering record and radiometric data.
-
terrestrial Planet Formation i the transition from oligarchic growth to chaotic growth
arXiv: Astrophysics, 2005Co-Authors: Scott J. Kenyon, Benjamin C. BromleyAbstract:We use a hybrid, multiannulus, n-body-coagulation code to investigate the growth of km-sized Planetesimals at 0.4-2 AU around a solar-type star. After a short runaway growth phase, protoPlanets with masses of roughly 10^26 g and larger form throughout the grid. When (i) the mass in these `oligarchs' is roughly comparable to the mass in Planetesimals and (ii) the surface density in oligarchs exceeds 2-3 g/sq cm at 1 AU, strong dynamical interactions among oligarchs produce a high merger rate which leads to the Formation of several terrestrial Planets. In disks with lower surface density, milder interactions produce several lower mass Planets. In all disks, the Planet Formation timescale is roughly 10-100 Myr, similar to estimates derived from the cratering record and radiometric data.
Ji-wei Xie - One of the best experts on this subject based on the ideXlab platform.
-
INFLUENCE OF STELLAR MULTIPLICITY ON Planet Formation. III. ADAPTIVE OPTICS IMAGING OF KEPLER STARS WITH GAS GIANT PlanetS
The Astrophysical Journal, 2015Co-Authors: Ji Wang, Debra A. Fischer, Elliott P. Horch, Ji-wei XieAbstract:As hundreds of gas giant Planets have been discovered, we study how these Planets form and evolve in different stellar environments, specifically in multiple stellar systems. In such systems, stellar companions may have a profound influence on gas giant Planet Formation and evolution via several dynamical effects such as truncation and perturbation. We select 84 Kepler Objects of Interest (KOIs) with gas giant Planet candidates. We obtain high-angular resolution images using telescopes with adaptive optics (AO) systems. Together with the AO data, we use archival radial velocity data and dynamical analysis to constrain the presence of stellar companions. We detect 59 stellar companions around 40 KOIs for which we develop methods of testing their physical association. These methods are based on color inFormation and galactic stellar population statistics. We find evidence of suppressive Planet Formation within 20 AU by comparing stellar multiplicity. The stellar multiplicity rate (MR) for Planet host stars is % within 20 AU. In comparison, the stellar MR is 18% ? 2% for the control sample, i.e., field stars in the solar neighborhood. The stellar MR for Planet host stars is 34% ? 8% for separations between 20 and 200 AU, which is higher than the control sample at 12% ? 2%. Beyond 200 AU, stellar MRs are comparable between Planet host stars and the control sample. We discuss the implications of the results on gas giant Planet Formation and evolution.
-
Influence of Stellar Multiplicity On Planet Formation. III. Adaptive Optics Imaging of Kepler Stars With Gas Giant Planets
arXiv: Earth and Planetary Astrophysics, 2015Co-Authors: Ji Wang, Debra A. Fischer, Elliott P. Horch, Ji-wei XieAbstract:As hundreds of gas giant Planets have been discovered, we study how these Planets form and evolve in different stellar environments, specifically in multiple stellar systems. In such systems, stellar companions may have a profound influence on gas giant Planet Formation and evolution via several dynamical effects such as truncation and perturbation. We select 84 Kepler Objects of Interest (KOIs) with gas giant Planet candidates. We obtain high-angular resolution images using telescopes with adaptive optics (AO) systems. Together with the AO data, we use archival radial velocity data and dynamical analysis to constrain the presence of stellar companions. We detect 59 stellar companions around 40 KOIs for which we develop methods of testing their physical association. These methods are based on color inFormation and galactic stellar population statistics. We find evidence of suppressive Planet Formation within 20 AU by comparing stellar multiplicity. The stellar multiplicity rate for Planet host stars is 0$^{+5}_{-0}$\% within 20 AU. In comparison, the stellar multiplicity rate is 18\%$\pm$2\% for the control sample, i.e., field stars in the solar neighborhood. The stellar multiplicity rate for Planet host stars is 34\%$\pm$8\% for separations between 20 and 200 AU, which is higher than the control sample at 12\%$\pm$2\%. Beyond 200 AU, stellar multiplicity rates are comparable between Planet host stars and the control sample. We discuss the implications of the results to gas giant Planet Formation and evolution.
-
influence of stellar multiplicity on Planet Formation ii Planets are less common in multiple star systems with separations smaller than 1500 au
The Astrophysical Journal, 2014Co-Authors: Ji Wang, Debra A. Fischer, Ji-wei Xie, David R CiardiAbstract:Almost half of the stellar systems in the solar neighborhood are made up of multiple stars. In multiple-star systems, Planet Formation is under the dynamical influence of stellar companions, and the Planet occurrence rate is expected to be different from that of single stars. There have been numerous studies on the Planet occurrence rate of single star systems. However, to fully understand Planet Formation, the Planet occurrence rate in multiple-star systems needs to be addressed. In this work, we infer the Planet occurrence rate in multiple-star systems by measuring the stellar multiplicity rate for Planet host stars. For a subsample of 56 Kepler Planet host stars, we use adaptive optics (AO) imaging and the radial velocity (RV) technique to search for stellar companions. The combination of these two techniques results in high search completeness for stellar companions. We detect 59 visual stellar companions to 25 Planet host stars with AO data. Three stellar companions are within 2'' and 27 within 6''. We also detect two possible stellar companions (KOI 5 and KOI 69) showing long-term RV acceleration. After correcting for a bias against Planet detection in multiple-star systems due to flux contamination, we find that Planet Formation is suppressed in multiple-star systems with separations smaller than 1500 AU. Specifically, we find that compared to single star systems, Planets in multiple-star systems occur 4.5 ± 3.2, 2.6 ± 1.0, and 1.7 ± 0.5 times less frequently when a stellar companion is present at a distance of 10, 100, and 1000 AU, respectively. This conclusion applies only to circumstellar Planets; the Planet occurrence rate for circumbinary Planets requires further investigation.
-
influence of stellar multiplicity on Planet Formation ii Planets are less common in multiple star systems with separations smaller than 1500 au
arXiv: Earth and Planetary Astrophysics, 2014Co-Authors: Ji Wang, Debra A. Fischer, Ji-wei Xie, David R CiardiAbstract:Almost half of the stellar systems in the solar neighborhood are made up of multiple stars. In multiple-star systems, Planet Formation is under the dynamical influence of stellar companions, and the Planet occurrence rate is expected to be different from that for single stars. There have been numerous studies on the Planet occurrence rate of single star systems. However, to fully understand Planet Formation, the Planet occurrence rate in multiple-star systems needs to be addressed. In this work, we {{infer}} the Planet occurrence rate in multiple-star systems by measuring the stellar multiplicity rate for Planet host stars. For a sub-sample of 56 $Kepler$ Planet host stars, we use adaptive optics (AO) imaging and the radial velocity (RV) technique to search for stellar companions. The combination of these two techniques results in high search completeness for stellar companions. We detect 59 visual stellar companions to 25 Planet host stars with AO data. {{Three stellar companions are within 2$^{\prime\prime}$, and 27 within 6$^{\prime\prime}$. We also detect 2 possible stellar companions (KOI 5 and KOI 69) showing long-term RV acceleration.}} After correcting for a bias against Planet detection in multiple-star systems due to flux contamination, we find that Planet Formation is suppressed in multiple-star systems with separations smaller than 1500 AU. Specifically, we find that compared to single star systems, Planets in multiple-star systems occur $4.5\pm3.2$, $2.6\pm1.0$, and $1.7\pm0.5$ times less frequently when a stellar companion is present at a distance of 10, 100, and 1000 AU, respectively. This conclusion applies only to circumstellar Planets; the Planet occurrence rate for circumbinary Planets requires further investigation.
Ji Wang - One of the best experts on this subject based on the ideXlab platform.
-
INFLUENCE OF STELLAR MULTIPLICITY ON Planet Formation. III. ADAPTIVE OPTICS IMAGING OF KEPLER STARS WITH GAS GIANT PlanetS
The Astrophysical Journal, 2015Co-Authors: Ji Wang, Debra A. Fischer, Elliott P. Horch, Ji-wei XieAbstract:As hundreds of gas giant Planets have been discovered, we study how these Planets form and evolve in different stellar environments, specifically in multiple stellar systems. In such systems, stellar companions may have a profound influence on gas giant Planet Formation and evolution via several dynamical effects such as truncation and perturbation. We select 84 Kepler Objects of Interest (KOIs) with gas giant Planet candidates. We obtain high-angular resolution images using telescopes with adaptive optics (AO) systems. Together with the AO data, we use archival radial velocity data and dynamical analysis to constrain the presence of stellar companions. We detect 59 stellar companions around 40 KOIs for which we develop methods of testing their physical association. These methods are based on color inFormation and galactic stellar population statistics. We find evidence of suppressive Planet Formation within 20 AU by comparing stellar multiplicity. The stellar multiplicity rate (MR) for Planet host stars is % within 20 AU. In comparison, the stellar MR is 18% ? 2% for the control sample, i.e., field stars in the solar neighborhood. The stellar MR for Planet host stars is 34% ? 8% for separations between 20 and 200 AU, which is higher than the control sample at 12% ? 2%. Beyond 200 AU, stellar MRs are comparable between Planet host stars and the control sample. We discuss the implications of the results on gas giant Planet Formation and evolution.
-
Influence of Stellar Multiplicity On Planet Formation. III. Adaptive Optics Imaging of Kepler Stars With Gas Giant Planets
arXiv: Earth and Planetary Astrophysics, 2015Co-Authors: Ji Wang, Debra A. Fischer, Elliott P. Horch, Ji-wei XieAbstract:As hundreds of gas giant Planets have been discovered, we study how these Planets form and evolve in different stellar environments, specifically in multiple stellar systems. In such systems, stellar companions may have a profound influence on gas giant Planet Formation and evolution via several dynamical effects such as truncation and perturbation. We select 84 Kepler Objects of Interest (KOIs) with gas giant Planet candidates. We obtain high-angular resolution images using telescopes with adaptive optics (AO) systems. Together with the AO data, we use archival radial velocity data and dynamical analysis to constrain the presence of stellar companions. We detect 59 stellar companions around 40 KOIs for which we develop methods of testing their physical association. These methods are based on color inFormation and galactic stellar population statistics. We find evidence of suppressive Planet Formation within 20 AU by comparing stellar multiplicity. The stellar multiplicity rate for Planet host stars is 0$^{+5}_{-0}$\% within 20 AU. In comparison, the stellar multiplicity rate is 18\%$\pm$2\% for the control sample, i.e., field stars in the solar neighborhood. The stellar multiplicity rate for Planet host stars is 34\%$\pm$8\% for separations between 20 and 200 AU, which is higher than the control sample at 12\%$\pm$2\%. Beyond 200 AU, stellar multiplicity rates are comparable between Planet host stars and the control sample. We discuss the implications of the results to gas giant Planet Formation and evolution.
-
influence of stellar multiplicity on Planet Formation ii Planets are less common in multiple star systems with separations smaller than 1500 au
The Astrophysical Journal, 2014Co-Authors: Ji Wang, Debra A. Fischer, Ji-wei Xie, David R CiardiAbstract:Almost half of the stellar systems in the solar neighborhood are made up of multiple stars. In multiple-star systems, Planet Formation is under the dynamical influence of stellar companions, and the Planet occurrence rate is expected to be different from that of single stars. There have been numerous studies on the Planet occurrence rate of single star systems. However, to fully understand Planet Formation, the Planet occurrence rate in multiple-star systems needs to be addressed. In this work, we infer the Planet occurrence rate in multiple-star systems by measuring the stellar multiplicity rate for Planet host stars. For a subsample of 56 Kepler Planet host stars, we use adaptive optics (AO) imaging and the radial velocity (RV) technique to search for stellar companions. The combination of these two techniques results in high search completeness for stellar companions. We detect 59 visual stellar companions to 25 Planet host stars with AO data. Three stellar companions are within 2'' and 27 within 6''. We also detect two possible stellar companions (KOI 5 and KOI 69) showing long-term RV acceleration. After correcting for a bias against Planet detection in multiple-star systems due to flux contamination, we find that Planet Formation is suppressed in multiple-star systems with separations smaller than 1500 AU. Specifically, we find that compared to single star systems, Planets in multiple-star systems occur 4.5 ± 3.2, 2.6 ± 1.0, and 1.7 ± 0.5 times less frequently when a stellar companion is present at a distance of 10, 100, and 1000 AU, respectively. This conclusion applies only to circumstellar Planets; the Planet occurrence rate for circumbinary Planets requires further investigation.
-
influence of stellar multiplicity on Planet Formation ii Planets are less common in multiple star systems with separations smaller than 1500 au
arXiv: Earth and Planetary Astrophysics, 2014Co-Authors: Ji Wang, Debra A. Fischer, Ji-wei Xie, David R CiardiAbstract:Almost half of the stellar systems in the solar neighborhood are made up of multiple stars. In multiple-star systems, Planet Formation is under the dynamical influence of stellar companions, and the Planet occurrence rate is expected to be different from that for single stars. There have been numerous studies on the Planet occurrence rate of single star systems. However, to fully understand Planet Formation, the Planet occurrence rate in multiple-star systems needs to be addressed. In this work, we {{infer}} the Planet occurrence rate in multiple-star systems by measuring the stellar multiplicity rate for Planet host stars. For a sub-sample of 56 $Kepler$ Planet host stars, we use adaptive optics (AO) imaging and the radial velocity (RV) technique to search for stellar companions. The combination of these two techniques results in high search completeness for stellar companions. We detect 59 visual stellar companions to 25 Planet host stars with AO data. {{Three stellar companions are within 2$^{\prime\prime}$, and 27 within 6$^{\prime\prime}$. We also detect 2 possible stellar companions (KOI 5 and KOI 69) showing long-term RV acceleration.}} After correcting for a bias against Planet detection in multiple-star systems due to flux contamination, we find that Planet Formation is suppressed in multiple-star systems with separations smaller than 1500 AU. Specifically, we find that compared to single star systems, Planets in multiple-star systems occur $4.5\pm3.2$, $2.6\pm1.0$, and $1.7\pm0.5$ times less frequently when a stellar companion is present at a distance of 10, 100, and 1000 AU, respectively. This conclusion applies only to circumstellar Planets; the Planet occurrence rate for circumbinary Planets requires further investigation.
S Chatterjee - One of the best experts on this subject based on the ideXlab platform.
-
inside out Planet Formation iii Planet disk interaction at the dead zone inner boundary
The Astrophysical Journal, 2015Co-Authors: Zhaohuan Zhu, Jonathan C Tan, S ChatterjeeAbstract:The Kepler mission has discovered more than 4000 exoPlanet candidates. Many of them are in systems with tightly packed inner Planets. Inside-out Planet Formation (IOPF) has been proposed as a scenario to explain these systems. It involves sequential in situ Planet Formation at the local pressure maximum of a retreating dead zone inner boundary (DZIB). Pebbles accumulate at this pressure trap, which builds up a pebble ring and then a Planet. The Planet is expected to grow in mass until it opens a gap, which helps to both truncate pebble accretion and also induce DZIB retreat that sets the location of Formation of the next Planet. This simple scenario may be modified if the Planet undergoes significant migration from its Formation location. Thus, Planet–disk interactions play a crucial role in the IOPF scenario. Here we present numerical simulations that first assess the degree of migration for Planets of various masses that are forming at the DZIB of an active accretion disk, where the effective viscosity is undergoing a rapid increase in the radially inward direction. We find that torques exerted on the Planet by the disk tend to trap the Planet at a location very close to the initial pressure maximum where it formed. We then study gap opening by these Planets to assess at what mass a significant gap is created. Finally, we present a simple model for DZIB retreat due to penetration of X-rays from the star to the disk midplane. Overall, these simulations help to quantify both the mass scale of first ("Vulcan") Planet Formation and the orbital separation to the location of second Planet Formation.
-
inside out Planet Formation iii Planet disk interaction at the dead zone inner boundary
arXiv: Earth and Planetary Astrophysics, 2015Co-Authors: Zhaohuan Zhu, Jonathan C Tan, S ChatterjeeAbstract:The Kepler mission has discovered more than 4000 exoPlanet candidates. Many are in systems with tightly packed inner Planets. Inside-Out Planet Formation (IOPF) has been proposed to explain these systems. It involves sequential in situ Planet Formation at the local pressure maximum of a retreating dead zone inner boundary (DZIB). Pebbles accumulate at this pressure trap, which builds up a ring, and then a Planet. The Planet is expected to grow until it opens a gap, which helps to both truncate pebble accretion and induce DZIB retreat that sets the location of Formation of the next Planet. This simple scenario may be modified if the Planet migrates significantly from its Formation location. Thus Planet-disk interactions play a crucial role in the IOPF scenario. We present numerical simulations that first assess migration of Planets of various masses that are forming at the DZIB of an active accretion disk, where the effective viscosity rapidly increases in the radially inward direction. We find that the disk's torques on the Planet tend to trap the Planet at a location very close to the initial pressure maximum where it formed. We then study gap opening by these Planets to assess at what mass a significant gap is created. Finally we present a simple model for DZIB retreat due to penetration of X-rays from the star to the disk midplane. Overall, these simulations help to quantify both the mass scale of first,"Vulcan," Planet Formation and the orbital separation to the location of second Planet Formation.
Debra A. Fischer - One of the best experts on this subject based on the ideXlab platform.
-
INFLUENCE OF STELLAR MULTIPLICITY ON Planet Formation. III. ADAPTIVE OPTICS IMAGING OF KEPLER STARS WITH GAS GIANT PlanetS
The Astrophysical Journal, 2015Co-Authors: Ji Wang, Debra A. Fischer, Elliott P. Horch, Ji-wei XieAbstract:As hundreds of gas giant Planets have been discovered, we study how these Planets form and evolve in different stellar environments, specifically in multiple stellar systems. In such systems, stellar companions may have a profound influence on gas giant Planet Formation and evolution via several dynamical effects such as truncation and perturbation. We select 84 Kepler Objects of Interest (KOIs) with gas giant Planet candidates. We obtain high-angular resolution images using telescopes with adaptive optics (AO) systems. Together with the AO data, we use archival radial velocity data and dynamical analysis to constrain the presence of stellar companions. We detect 59 stellar companions around 40 KOIs for which we develop methods of testing their physical association. These methods are based on color inFormation and galactic stellar population statistics. We find evidence of suppressive Planet Formation within 20 AU by comparing stellar multiplicity. The stellar multiplicity rate (MR) for Planet host stars is % within 20 AU. In comparison, the stellar MR is 18% ? 2% for the control sample, i.e., field stars in the solar neighborhood. The stellar MR for Planet host stars is 34% ? 8% for separations between 20 and 200 AU, which is higher than the control sample at 12% ? 2%. Beyond 200 AU, stellar MRs are comparable between Planet host stars and the control sample. We discuss the implications of the results on gas giant Planet Formation and evolution.
-
Influence of Stellar Multiplicity On Planet Formation. III. Adaptive Optics Imaging of Kepler Stars With Gas Giant Planets
arXiv: Earth and Planetary Astrophysics, 2015Co-Authors: Ji Wang, Debra A. Fischer, Elliott P. Horch, Ji-wei XieAbstract:As hundreds of gas giant Planets have been discovered, we study how these Planets form and evolve in different stellar environments, specifically in multiple stellar systems. In such systems, stellar companions may have a profound influence on gas giant Planet Formation and evolution via several dynamical effects such as truncation and perturbation. We select 84 Kepler Objects of Interest (KOIs) with gas giant Planet candidates. We obtain high-angular resolution images using telescopes with adaptive optics (AO) systems. Together with the AO data, we use archival radial velocity data and dynamical analysis to constrain the presence of stellar companions. We detect 59 stellar companions around 40 KOIs for which we develop methods of testing their physical association. These methods are based on color inFormation and galactic stellar population statistics. We find evidence of suppressive Planet Formation within 20 AU by comparing stellar multiplicity. The stellar multiplicity rate for Planet host stars is 0$^{+5}_{-0}$\% within 20 AU. In comparison, the stellar multiplicity rate is 18\%$\pm$2\% for the control sample, i.e., field stars in the solar neighborhood. The stellar multiplicity rate for Planet host stars is 34\%$\pm$8\% for separations between 20 and 200 AU, which is higher than the control sample at 12\%$\pm$2\%. Beyond 200 AU, stellar multiplicity rates are comparable between Planet host stars and the control sample. We discuss the implications of the results to gas giant Planet Formation and evolution.
-
influence of stellar multiplicity on Planet Formation ii Planets are less common in multiple star systems with separations smaller than 1500 au
The Astrophysical Journal, 2014Co-Authors: Ji Wang, Debra A. Fischer, Ji-wei Xie, David R CiardiAbstract:Almost half of the stellar systems in the solar neighborhood are made up of multiple stars. In multiple-star systems, Planet Formation is under the dynamical influence of stellar companions, and the Planet occurrence rate is expected to be different from that of single stars. There have been numerous studies on the Planet occurrence rate of single star systems. However, to fully understand Planet Formation, the Planet occurrence rate in multiple-star systems needs to be addressed. In this work, we infer the Planet occurrence rate in multiple-star systems by measuring the stellar multiplicity rate for Planet host stars. For a subsample of 56 Kepler Planet host stars, we use adaptive optics (AO) imaging and the radial velocity (RV) technique to search for stellar companions. The combination of these two techniques results in high search completeness for stellar companions. We detect 59 visual stellar companions to 25 Planet host stars with AO data. Three stellar companions are within 2'' and 27 within 6''. We also detect two possible stellar companions (KOI 5 and KOI 69) showing long-term RV acceleration. After correcting for a bias against Planet detection in multiple-star systems due to flux contamination, we find that Planet Formation is suppressed in multiple-star systems with separations smaller than 1500 AU. Specifically, we find that compared to single star systems, Planets in multiple-star systems occur 4.5 ± 3.2, 2.6 ± 1.0, and 1.7 ± 0.5 times less frequently when a stellar companion is present at a distance of 10, 100, and 1000 AU, respectively. This conclusion applies only to circumstellar Planets; the Planet occurrence rate for circumbinary Planets requires further investigation.
-
influence of stellar multiplicity on Planet Formation ii Planets are less common in multiple star systems with separations smaller than 1500 au
arXiv: Earth and Planetary Astrophysics, 2014Co-Authors: Ji Wang, Debra A. Fischer, Ji-wei Xie, David R CiardiAbstract:Almost half of the stellar systems in the solar neighborhood are made up of multiple stars. In multiple-star systems, Planet Formation is under the dynamical influence of stellar companions, and the Planet occurrence rate is expected to be different from that for single stars. There have been numerous studies on the Planet occurrence rate of single star systems. However, to fully understand Planet Formation, the Planet occurrence rate in multiple-star systems needs to be addressed. In this work, we {{infer}} the Planet occurrence rate in multiple-star systems by measuring the stellar multiplicity rate for Planet host stars. For a sub-sample of 56 $Kepler$ Planet host stars, we use adaptive optics (AO) imaging and the radial velocity (RV) technique to search for stellar companions. The combination of these two techniques results in high search completeness for stellar companions. We detect 59 visual stellar companions to 25 Planet host stars with AO data. {{Three stellar companions are within 2$^{\prime\prime}$, and 27 within 6$^{\prime\prime}$. We also detect 2 possible stellar companions (KOI 5 and KOI 69) showing long-term RV acceleration.}} After correcting for a bias against Planet detection in multiple-star systems due to flux contamination, we find that Planet Formation is suppressed in multiple-star systems with separations smaller than 1500 AU. Specifically, we find that compared to single star systems, Planets in multiple-star systems occur $4.5\pm3.2$, $2.6\pm1.0$, and $1.7\pm0.5$ times less frequently when a stellar companion is present at a distance of 10, 100, and 1000 AU, respectively. This conclusion applies only to circumstellar Planets; the Planet occurrence rate for circumbinary Planets requires further investigation.
