scholarly journals The HADES RV Programme with HARPS-N at TNG

2018 ◽  
Vol 617 ◽  
pp. A104 ◽  
Author(s):  
M. Pinamonti ◽  
M. Damasso ◽  
F. Marzari ◽  
A. Sozzetti ◽  
S. Desidera ◽  
...  
Keyword(s):  
Planetary System ◽  
Orbital Evolution ◽  
Dynamical Analysis ◽  
Outer Planet ◽  
Orbital Configuration ◽  
Orbital Instability ◽  
Astrometric Data ◽  
Long Term Trend ◽  
Orbital Solution

We present 20 yr of radial velocity (RV) measurements of the M1 dwarf Gl15A, combining five years of intensive RV monitoring with the HARPS-N spectrograph with 15 yr of archival HIRES/Keck RV data. We have carried out an MCMC-based analysis of the RV time series, inclusive of Gaussian Process (GP) approach to the description of stellar activity induced RV variations. Our analysis confirms the Keplerian nature and refines the orbital solution for the 11.44-day period super Earth, Gl15A b, reducing its amplitude to 1.68−0.18+0.17 m s−1 (M sin i = 3.03−0.44+0.46 M⊕), and successfully models a long-term trend in the combined RV dataset in terms of a Keplerian orbit with a period around 7600 days and an amplitude of 2.5−1.0+1.3 m s−1, corresponding to a super-Neptune mass (M sin i = 36−18+25 M⊕) planetary companion. We also discuss the present orbital configuration of Gl15A planetary system in terms of the possible outcomes of Lidov–Kozai interactions with the wide-separation companion Gl15B in a suite of detailed numerical simulations. In order to improve the results of the dynamical analysis, we have derived a new orbital solution for the binary system, combining our RV measurements with astrometric data from the WDS catalogue. The eccentric Lidov–Kozai analysis shows the strong influence of Gl15B on the Gl15A planetary system, which can produce orbits compatible with the observed configuration for initial inclinations of the planetary system between 75° and 90°, and can also enhance the eccentricity of the outer planet well above the observed value, even resulting in orbital instability, for inclinations around 0° and 15°−30°. The Gl15A system is the multi-planet system closest to Earth, at 3.56 pc, and hosts the longest period RV sub-Jovian mass planet discovered so far. Its orbital architecture constitutes a very important laboratory for the investigation of formation and orbital evolution scenarios for planetary systems in binary stellar systems.

scholarly journals Orbital determination and dynamics of resonant extrasolar planetary systems

2007 ◽  
Vol 3 (S249) ◽  
pp. 427-440 ◽  
Author(s):  
C. Beaugé ◽  
S. Ferraz-Mello ◽  
T. A. Michtchenko ◽  
C. A. Giuppone
Keyword(s):  
Planetary System ◽  
Planetary Systems ◽  
Orbital Evolution ◽  
Dynamical Analysis ◽  
Dynamical Structure ◽  
Mean Motion Resonances ◽  
Orbital Decay ◽  
Complementary Part ◽  
Resonant Systems ◽  
Orbital Determination

AbstractIn this communication we review some properties and applications of mean-motion resonances in extrasolar planetary systems, with particular emphasis on the 2/1 commensurability. A first part is devoted to the dynamical structure of the 2/1 resonance, including (but not restricted to) the so-called apsidal corotations. In a second part we discuss the orbital evolution of resonant systems under the effects of non-conservative forces. Special attention is given to the use of apsidal corotations as markers of largescale orbital decay, possibly due to disk-planet interactions in primordial times. Finally, we analyze the interplay between dynamical analysis and orbital fitting. Using the HD82943 planetary system as an example, we discuss: (i) up to what point present orbital fits allow us to distinguish between different resonant configurations, and (ii) in what ways may the dynamical structure of resonances be used as a complementary part of the orbital fitting process.

scholarly journals Resonance in the K2-19 system is at odds with its high reported eccentricities

2020 ◽  
Vol 496 (3) ◽  
pp. 3101-3111
Author(s):  
Antoine C Petit ◽  
Erik A Petigura ◽  
Melvyn B Davies ◽  
Anders Johansen
Keyword(s):  
Planet Formation ◽  
Planetary System ◽  
Recent Analysis ◽  
Circular Orbits ◽  
Tidal Dissipation ◽  
Outer Planets ◽  
Mean Motion ◽  
Orbital Configuration ◽  
Orbital Solution ◽  
Rule Out

ABSTRACT K2-19 hosts a planetary system composed of two outer planets, b and c, with size of 7.0 ± 0.2 R⊕ and 4.1 ± 0.2 R⊕, and an inner planet, d, with a radius of 1.11 ± 0.05 R⊕. A recent analysis of Transit-Timing Variations (TTVs) suggested b and c are close to but not in 3:2 mean motion resonance (MMR) because the classical resonant angles circulate. Such an architecture challenges our understanding of planet formation. Indeed, planet migration through the protoplanetary disc should lead to a capture into the MMR. Here, we show that the planets are in fact, locked into the 3:2 resonance despite circulation of the conventional resonant angles and aligned periapses. However, we show that such an orbital configuration cannot be maintained for more than a few hundred million years due to the tidal dissipation experienced by planet d. The tidal dissipation remains efficient because of a secular forcing of the innermost planet eccentricity by planets b and c. While the observations strongly rule out an orbital solution where the three planets are on close to circular orbits, it remains possible that a fourth planet is affecting the TTVs such that the four planet system is consistent with the tidal constraints.

scholarly journals The CARMENES search for exoplanets around M dwarfs

2020 ◽  
Vol 638 ◽  
pp. A16
Author(s):  
T. Trifonov ◽  
M. H. Lee ◽  
M. Kürster ◽  
Th. Henning ◽  
E. Grishin ◽  
...  
Keyword(s):  
Planetary System ◽  
Stable Region ◽  
M Dwarfs ◽  
Orbital Parameters ◽  
Orbital Decay ◽  
Secular Theory ◽  
Orbital Configuration ◽  
Large Phase ◽  
M Dwarf

Context. GJ 1148 is an M-dwarf star hosting a planetary system composed of two Saturn-mass planets in eccentric orbits with periods of 41.38 and 532.02 days. Aims. We reanalyze the orbital configuration and dynamics of the GJ 1148 multi-planetary system based on new precise radial velocity measurements taken with CARMENES. Methods. We combined new and archival precise Doppler measurements from CARMENES with those available from HIRES for GJ 1148 and modeled these data with a self-consistent dynamical model. We studied the orbital dynamics of the system using the secular theory and direct N-body integrations. The prospects of potentially habitable moons around GJ 1148 b were examined. Results. The refined dynamical analyses show that the GJ 1148 system is long-term stable in a large phase-space of orbital parameters with an orbital configuration suggesting apsidal alignment, but not in any particular high-order mean-motion resonant commensurability. GJ 1148 b orbits inside the optimistic habitable zone (HZ). We find only a narrow stability region around the planet where exomoons can exist. However, in this stable region exomoons exhibit quick orbital decay due to tidal interaction with the planet. Conclusions. The GJ 1148 planetary system is a very rare M-dwarf planetary system consisting of a pair of gas giants, the inner of which resides in the HZ. We conclude that habitable exomoons around GJ 1148 b are very unlikely to exist.

scholarly journals An alternative stable solution for the Kepler-419 system, obtained with the use of a genetic algorithm

2018 ◽  
Vol 620 ◽  
pp. A88
Author(s):  
D. D. Carpintero ◽  
M. Melita
Keyword(s):  
Genetic Algorithm ◽  
Planetary System ◽  
Stable Solution ◽  
Orbital Evolution ◽  
Orbital Elements ◽  
Single Period ◽  
Transit Times ◽  
Observational Errors ◽  
Free Parameters

Context. The mid-transit times of an exoplanet may be nonperiodic. The variations in the timing of the transits with respect to a single period, that is, the transit timing variations (TTVs), can sometimes be attributed to perturbations by other exoplanets present in the system, which may or may not transit the star. Aims. Our aim is to compute the mass and the six orbital elements of an nontransiting exoplanet, given only the central times of transit of the transiting body. We also aim to recover the mass of the star and the mass and orbital elements of the transiting exoplanet, suitably modified in order to decrease the deviation between the observed and the computed transit times by as much as possible. Methods. We have applied our method, based on a genetic algorithm, to the Kepler-419 system. Results. We were able to compute all 14 free parameters of the system, which, when integrated in time, give transits within the observational errors. We also studied the dynamics and the long-term orbital evolution of the Kepler-419 planetary system as defined by the orbital elements computed by us, in order to determine its stability.

NAEP Trends: Main NAEP vs. Long-Term Trend

2010 ◽  
Author(s):  
Albert E. Beaton ◽  
James R. Chromy
Keyword(s):  
Term Trend ◽  
Long Term Trend

Institutionalizing the Liberal Creed

2017 ◽  
Author(s):  
Ronen Mandelkern
Keyword(s):  
Political Influence ◽  
Institutional Entrepreneurship ◽  
Political Decision ◽  
Economic Liberalism ◽  
Market Economic ◽  
Ministry Of Finance ◽  
Political Entrepreneurs ◽  
Long Term Trend ◽  
Political Decision Making

This chapter analyzes the role Israeli economists have played as purveyors of pro-market economic ideas and political entrepreneurs of economic liberalization in Israel. Israeli economists were strongly committed to economic liberalism already in the 1950s, but they were lacking decisive political influence. Two mechanisms increased their power over policy. First, long-term institutional changes gradually eroded “political” decision-making mechanism and opened the way to greater involvement of professional economists. This long-term trend was joined and reinforced by economists’ institutional entrepreneurship at the height of the 1980s economic crisis, when they initiated changes of macroeconomic governance. These changes enhanced the political power of the Ministry of Finance and the Bank of Israel and supported the institutionalization of neoliberalism in Israel.

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