scholarly journals Probing the impact of stellar duplicity on the frequency of giant planets: Final results of our VLT/NACO survey

2010 ◽  
Vol 6 (S276) ◽  
pp. 409-410 ◽  
Author(s):  
Anne Eggenberger ◽  
Stéphane Udry ◽  
Gaël Chauvin ◽  
Thierry Forveille ◽  
Jean-Luc Beuzit ◽  
...  
Keyword(s):  
Adaptive Optics ◽  
Proper Motion ◽  
Binary Systems ◽  
Dynamical Evolution ◽  
Giant Planets ◽  
The Other ◽  
Physical Association ◽  
Short Period ◽  
Solar Type ◽  
The Impact

AbstractIf it is commonly agreed that the presence of a (moderately) close stellar companion affects the formation and the dynamical evolution of giant planets, the frequency of giant planets residing in binary systems separated by less than 100 AU is unknown. To address this issue, we have conducted with VLT/NACO a systematic adaptive optics search for moderately close stellar companions to 130 nearby solar-type stars. According to the data from Doppler surveys, half of our targets host at least one planetary companion, while the other half show no evidence for short-period giant planets. We present here the final results of our survey, which include a new series of second-epoch measurements to test for common proper motion. The new observations confirm the physical association of two companion candidates and prove the unbound status of many others. These results strengthen our former conclusion that circumstellar giant planets are slightly less frequent in binaries with mean semimajor axes between 35 and 100 AU than in wider systems or around single stars.

scholarly journals Strategic Exploration of Exoplanets and Disks with Subaru: SEEDS

2010 ◽  
Vol 6 (S276) ◽  
pp. 436-437
Author(s):  
Nobuhiko Kusakabe ◽  
Motohide Tamura ◽  
Ryo Kandori ◽  
Tomoyuki Kudo ◽  
Jun Hashimoto ◽  
...  
Keyword(s):  
Adaptive Optics ◽  
Young Stars ◽  
Giant Planets ◽  
Current Status ◽  
High Contrast ◽  
Direct Imaging ◽  
Instrument Performance ◽  
Early Results ◽  
Solar Type ◽  
Adaptive Optics System

AbstractThe purpose of the SEEDS project (PI: M. Tamura) is to conduct a direct imaging survey, searching for giant planets as well as protoplanetary/debris disks at a few to a few tens of AU regions around 500 nearby solar-type or more massive young stars with the combination of the Subaru 8.2m telescope, the new high-contrast instrument HiCIAO, and the adaptive optics system AO188. After instrument performance verification, the SEEDS survey successfully started in October 2009. We have already detected many companion candidates to be followed-up, and clear and much better detections of disks or details of known disks structures. In this contribution, we will outline our goal, current status, early results, and future instrumentation plans.

scholarly journals Orbital evolution of short-period comets with high values of the Tisserand constant

2006 ◽  
Vol 2 (S236) ◽  
pp. 35-42 ◽  
Author(s):  
N.Yu. Emel'yanenko
Keyword(s):  
Dynamical Evolution ◽  
Orbital Evolution ◽  
Giant Planets ◽  
Time Interval ◽  
Short Period

AbstractThe orbital evolution of comets with high values of the Tisserand constant is studied for a time interval of 800 years. Scenarios of dynamical evolution are obtained for 85 comets. Particular features of the orbital evolution of the comets of this class are singled out. The orbits of all comets are tangent to the orbit of Jupiter and have a steadily low inclination. For 80% of comets, the evolution scenario includes a timespan in which the comets move in low-eccentricity orbits. The possibility is analyzed of a change in the Tisserand constant and of a transition of the comet to be controlled by other giant planets.

scholarly journals Active bodies in the near-Earth region: The tenuous boundary between comets and asteroids

2015 ◽  
Vol 10 (S318) ◽  
pp. 142-143
Author(s):  
Julio A. Fernández ◽  
Andrea Sosa
Keyword(s):  
Dynamical Evolution ◽  
The Other ◽  
General Definition ◽  
The Sun ◽  
Main Belt ◽  
Close Encounters ◽  
The Earth ◽  
Bare Nucleus ◽  
Short Period ◽  
Near Earth Asteroids

AbstractWe analyze the dynamics and activity observed in bodies approaching the Earth (perihelion distancesq< 1.3 au) in short-period orbits (P< 20 yr), which essentially are near-Earth Jupiter Family Comets (NEJFCs) and near-Earth asteroids (NEAs). In the general definition, comets are “active”, i.e. they show some coma, while asteroids are “inactive”, i.e. they only show a bare nucleus. Besides their activity, NEJFCs are distinguished from NEAs by their dynamical evolution: NEJFCs move on unstable orbits subject to frequent close encounters with Jupiter, whereas NEA orbits are much more stable and tend to avoid close encounters with Jupiter. However, some JFCs are found to move on stable, asteroidal-type orbits, so the question arises if these objects are asteroids that have become active, perhaps upon approach to the Sun. In this sense they may be regarded as the counterparts of the main-belt comets (Hsieh & Jewitt 2006). On the other hand, some seemingly inert NEAs move on unstable, comet-type orbits, so the question about what is a comet and what is an asteroid has become increasingly complex.

scholarly journals Habitable planet formation in extreme planetary systems: systems with multiple stars and/or multiple planets

2007 ◽  
Vol 3 (S249) ◽  
pp. 319-324
Author(s):  
Nader Haghighipour
Keyword(s):  
Binary Stars ◽  
Binary Systems ◽  
Planet Formation ◽  
Planetary Systems ◽  
Dynamical Evolution ◽  
Giant Planets ◽  
Habitable Planets ◽  
Multiple Stars ◽  
Habitable Zones ◽  
Habitable Planet

AbstractUnderstanding the formation and dynamical evolution of habitable planets in extrasolar planetary systems is a challenging task. In this respect, systems with multiple giant planets and/or multiple stars present special complications. The formation of habitable planets in these environments is strongly affected by the dynamics of their giant planets and/or their stellar companions. These objects have profound effects on the structure of the disk of planetesimals and protoplanetary objects in which terrestrial-class planets are formed. To what extent the current theories of planet formation can be applied to such “extreme” planetary systems depends on the dynamical characteristics of their planets and/or their binary stars. In this paper, I present the results of a study of the possibility of the existence of Earth-like objects in systems with multiple giant planets (namely υ Andromedae, 47 UMa, GJ 876, and 55 Cnc) and discuss the dynamics of the newly discovered Neptune-sized object in 55 Cnc system. I will also review habitable planet formation in binary systems and present the results of a systematic search of the parameter-space for which Earth-like objects can form and maintain long-term stable orbits in the habitable zones of binary stars.

scholarly journals LAMOST telescope reveals that Neptunian cousins of hot Jupiters are mostly single offspring of stars that are rich in heavy elements

2017 ◽  
Vol 115 (2) ◽  
pp. 266-271 ◽  
Author(s):  
Subo Dong ◽  
Ji-Wei Xie ◽  
Ji-Lin Zhou ◽  
Zheng Zheng ◽  
Ali Luo
Keyword(s):  
Main Sequence ◽  
The Other ◽  
Heavy Elements ◽  
Main Sequence Stars ◽  
Hot Jupiters ◽  
Transiting Planets ◽  
Short Period ◽  
Data Release ◽  
Order Of Magnitude ◽  
Solar Type

We discover a population of short-period, Neptune-size planets sharing key similarities with hot Jupiters: both populations are preferentially hosted by metal-rich stars, and both are preferentially found in Kepler systems with single-transiting planets. We use accurate Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) Data Release 4 (DR4) stellar parameters for main-sequence stars to study the distributions of short-period (1d<P<10d)Kepler planets as a function of host star metallicity. The radius distribution of planets around metal-rich stars is more “puffed up” compared with that around metal-poor hosts. In two period–radius regimes, planets preferentially reside around metal-rich stars, while there are hardly any planets around metal-poor stars. One is the well-known hot Jupiters, and the other one is a population of Neptune-size planets (2R⊕≲Rp≲6R⊕), dubbed “Hoptunes.” Also like hot Jupiters, Hoptunes occur more frequently in systems with single-transiting planets although the fraction of Hoptunes occurring in multiples is larger than that of hot Jupiters. About 1% of solar-type stars host Hoptunes, and the frequencies of Hoptunes and hot Jupiters increase with consistent trends as a function of [Fe/H]. In the planet radius distribution, hot Jupiters and Hoptunes are separated by a “valley” at approximately Saturn size (in the range of 6R⊕≲Rp≲10R⊕), and this “hot-Saturn valley” represents approximately an order-of-magnitude decrease in planet frequency compared with hot Jupiters and Hoptunes. The empirical “kinship” between Hoptunes and hot Jupiters suggests likely common processes (migration and/or formation) responsible for their existence.

scholarly journals Dynamical evolution of near-Sun objects

2014 ◽  
Vol 9 (S310) ◽  
pp. 126-129
Author(s):  
Vacheslav V. Emel'yanenko ◽  
Mikhail A. Shelyakov
Keyword(s):  
Dynamical Evolution ◽  
Orbital Evolution ◽  
The Other ◽  
Secular Perturbations ◽  
The Past ◽  
Other Hand ◽  
Short Period ◽  
Near Earth Objects

AbstractThe dynamical evolution of short-period objects having perihelia at small heliocentric distances is discussed. We have investigated the motion of multiple-apparition members of the Marsden and Kracht sungrazing groups. The orbital evolution of these objects on timescales < 10 Kyr is mainly determined by the Kozai-Lidov secular perturbations. These objects are dynamically connected with high-inclination near-Earth objects. On the other hand, we have found several observed near-Earth objects that evolve in the same way, reaching small perihelion distances on short timescales in the past.

scholarly journals Science with Small Observatory Instruments

2001 ◽  
Vol 24 (3) ◽  
pp. 315-315
Author(s):  
Ron G. Samec
Keyword(s):  
Binary Systems ◽  
Binary Star ◽  
Local Level ◽  
Type Systems ◽  
Good Science ◽  
Gas Streams ◽  
Short Period ◽  
Solar Type ◽  
Large Period ◽  
Productive Research

Good science can be done with small instruments. Very productive research in the area of short period interacting binary systems has been conducted by the authors with PMT’s and small CCD cameras attached to 0.28 m to 0.9-m instruments. A summary of important results over the past fourteen years is presented along with current work on the interesting semidetached and contact solar type systems TY UMa, V523 Cas, CN And, VZ Psc and BE Cep. Light curve asymmetries in CN And, BE Cep and possibly others indicate the presence of gas streams. This may signal that they are undergoing evolution into contact, an important but rarely observed stage in binary star evolution. Period studies are presented for each of the systems, documenting interesting orbital histories. V523 Cas and TY UMa display large period changes giving evidence of a light time effect due to a third body. This research has been largely supported at the local level and by small research grants from the American Astronomical Society.

scholarly journals The dynamical evolution of close-in binary systems formed by a super-Earth and its host star

2020 ◽  
Vol 641 ◽  
pp. A109
Author(s):  
S. H. Luna ◽  
H. D. Navone ◽  
M. D. Melita
Keyword(s):  
Binary System ◽  
Time Evolution ◽  
Binary Systems ◽  
Initial Conditions ◽  
Equations Of Motion ◽  
Dynamical Evolution ◽  
The Other ◽  
Rheological Parameters ◽  
Orbital Elements ◽  
Rotational Evolution

Aims. The aim of this work is to develop a formalism for the study of the secular evolution of a binary system which includes interaction due to the tides that each body imparts on the other. We also consider the influence of the J2-related secular terms on the orbital evolution and the torque, caused by the triaxiality, on the rotational evolution, both of which are associated only to one of the bodies. We apply these set of equations to the study of the orbital and rotational evolution of a binary system composed of a rocky planet and its host star in order to characterize the dynamical evolution at work, particularly near spin-orbit resonances. Methods. We used the equations of motion that give the time evolution of the orbital elements and the spin rates of each body to study the dynamical evolution of the Kepler-21 system as an example of how the formalism that we have developed can be applied. Results. We obtained a set of equations of motion without singularities for vanishing eccentricities and inclinations. This set gives, on one hand, the time evolution of the orbital elements due to the tidal potentials generated by both members of the system as well as the oblateness of one of them. On the other hand, it gives the time evolution of the stellar spin rate due to the corresponding tidal torque and of the planet’s rotation angle due to both the tidal and triaxiality-induced torques. We found that for the parameters and the initial conditions explored here, the tidally and triaxiality-induced modifications of the tidal modes can be more significative than expected and that the time of tidal synchronization strongly depends on the values of the rheological parameters.

scholarly journals Li and Be Depletion in Stars with Exoplanets?

2011 ◽  
Vol 7 (S282) ◽  
pp. 466-467
Author(s):  
E. Delgado Mena ◽  
G. Israelian ◽  
J. I. González Hernández ◽  
R. Rebolo ◽  
N. C. Santos ◽  
...  
Keyword(s):  
Planetary Systems ◽  
Giant Planets ◽  
The Other ◽  
Light Elements ◽  
Other Hand ◽  
Wide Range ◽  
Solar Type ◽  
Effective Temperatures ◽  
Host Stars

AbstractIt is well known that stars with orbiting giant planets have a higher metallic content than stars without detected planets. In addition, we have found that solar-type stars with planets present an extra Li depletion when compared with field stars. On the other hand, Be needs a greater temperature to be destroyed, so we may find such a relation in cooler stars, whose convective envelopes are deep enough to carry material to layers where Be can be burned. We present Li and Be abundances for an extensive sample of stars with and without detected planets, covering a wide range of effective temperatures (4700-6500 K) with the aim of studying possible differences between the abundances of both groups. The processes that take place in the formation of planetary systems may affect the mixing of material inside their host stars and hence the abundances of light elements.

scholarly journals Pebbles versus planetesimals

2020 ◽  
Vol 640 ◽  
pp. A21 ◽  
Author(s):  
N. Brügger ◽  
R. Burn ◽  
G. A. L. Coleman ◽  
Y. Alibert ◽  
W. Benz
Keyword(s):  
Planet Formation ◽  
Initial Conditions ◽  
Giant Planet ◽  
Mass Range ◽  
Giant Planets ◽  
The Other ◽  
Type I ◽  
Core Mass ◽  
Accretion Model ◽  
The Impact

Context. In the core accretion scenario of giant planet formation, a massive core forms first and then accretes a gaseous envelope. In the discussion of how this core forms, some divergences appear. The first scenarios of planet formation predict the accretion of kilometre-sized bodies called planetesimals, while more recent works suggest growth by the accretion of pebbles, which are centimetre-sized objects. Aims. These two accretion models are often discussed separately and our aim here is to compare the outcomes of the two models with identical initial conditions. Methods. The comparison is done using two distinct codes, one that computes the planetesimal accretion and the other the pebble accretion. All the other components of the simulated planet growth are computed identically in the two models: the disc, the accretion of gas, and the migration. Using a population synthesis approach, we compare planet simulations and study the impact of the two solid accretion models, focusing on the formation of single planets. Results. We find that the outcomes of the populations are strongly influenced by the accretion model. The planetesimal model predicts the formation of more giant planets, while the pebble accretion model forms more super-Earth-mass planets. This is due to the pebble isolation mass (Miso) concept, which prevents planets formed by pebble accretion to accrete gas efficiently before reaching Miso. This translates into a population of planets that are not heavy enough to accrete a consequent envelope, but that are in a mass range where type I migration is very efficient. We also find higher gas mass fractions for a given core mass for the pebble model compared to the planetesimal model, caused by luminosity differences. This also implies planets with lower densities, which could be confirmed observationally. Conclusions. We conclude that the two models produce different outputs. Focusing on giant planets, the sensitivity of their formation differs: for the pebble accretion model, the time at which the embryos are formed and the period over which solids are accreted strongly impact the results, while the population of giant planets formed by planetesimal accretion depends on the planetesimal size and on the splitting in the amount of solids available to form planetesimals.

Sign in / Sign up

Export Citation Format

Share Document