Refining the Orbits of the Planets in HD 207832

Total Page:16

File Type:pdf, Size:1020Kb

Refining the Orbits of the Planets in HD 207832 Refining the orbits of the planets in HD 207832 Emil Zadera Lund Observatory Lund University 2017-EXA119 Degree project of 15 higher education credits June 2017 Supervisor: Alex Mustill Lund Observatory Box 43 SE-221 00 Lund Sweden Abstract The star, HD 207832, has two Jupiter-like planets on orbits with poorly constrained ec- +0:22 +0:18 centricities. The eccentricities are 0.27−0:10 and 0.13−0:05 respectively. Notably, the two sigma error allows eccentricities up to 0.71 for one of the planets. Due to the large error bars, one aim of this project is to refine them. This is done by simulating the system for different initial eccentricities within the two sigma error bars for both of the planets. If a simulated system is shown to be unstable, the initial eccentricities used in the simulation, can not describe the observed system, HD 207832. In this project, it has been shown that the outer planet, in HD 207832, can not exceed an initial eccentricity of 0.6 in order for the system to remain stable. Furthermore, The level of chaos of the two planets, in each simulated system, is inves- tigated with the use of Fourier analysis. A code is written which calculates the Fourier transform of the eccentricities. The code then counts the number of peaks in the spec- trum which determines the level of chaos in the system. In this project, the use of Fourier analysis, to determine the level of chaos, is shown to be useful when comparing the chaos between simulations that have similar integration times. It is also shown that the outcome in each simulation is very sensitive to the fixed timestep used. It is highlighted that small changes in the timestep can change the outcome of the simulation in the sense of making a stable system, unstable. HD 207832, further, has a habitable zone, where a planet can support liquid water on its surface, that is located between the two Jupiter-like planets. Radial velocity measurements have yet not been able to detect any planet within this zone. In this project, stable orbits for a small planet, within the habitable zone, are thus searched for. This is done for the nominal system of HD 207832, and for the case when one sigma has been subtracted from the eccentricities of the two Jupiter-like planets. In this project, by the use of test particles, a few orbits are shown to be stable over at least 250 Myr in both of the simulated systems. It is thus possible that HD 207832 has a habitable planet that has not yet been detected. Key words: HD 207832 { eccentricity space { chaos { habitable zone { stability Popul¨arvetenskaplig beskrivning Vad Klarar Dessa Exoplaneterna Av? V˚ardatabas av dokumenterade exoplaneter ¨aruppe i tusental och nya planeter uppt¨aks varje dag. Ofta ¨ardessa planeterna bundna till en stj¨arna,precis som planeterna i v˚arat solsystem ¨arbundna till solen. Vissa av de planetiska systemen ¨argoda kandidater till att inneh˚allaplaneter som liknar jorden, medan andra har f¨orstr¨angaf¨orh˚allanden.Oavsett m¨angdenav exoplaneter, ¨ardet viktig att f¨oljaupp och kontrollera hur v¨aldessa planet- systemen ¨arbeskrivna av parametrarna som ¨argivna i v˚arandatabas f¨oratt kunna analy- sera dem vidare. I detta projekt bidrar vi med information till databasen, av de or¨akneligt m˚angaexoplanet-systemen, genom att titta p˚aett av dem. Detta system best˚arav tv˚a planeter, stora som Jupiter, som circulerar omkring en stj¨arnavid namn HD 207832. Vi inspekterar systemets parametrar och ¨aven m¨ojlighetenav att en oidentifierad, beboelig planet skulle kunna befinna sig i systemet. Varf¨orHD 207832? M¨atningarnasom togs f¨oratt verifiera detta systemet, tyder p˚aatt de tv˚abefintliga plan- eterna har en mycket stor os¨akerhet i sina parametrar. Enligt m¨atningarnaskulle plan- eterna kunna befinna sig p˚amycket exotiska banor. Med exotisk i detta samanhanget menar vi att skillnaden mellan den h¨ogstaoch den l¨agstahastigheten f¨oren planet i sin om- loppsbana skulle kunna vara stor. Hastigheten hoss en planet ¨arkopplad till planet-banans eccentricitet, som ¨aren parameter som avg¨orplanetens n¨armasteposition till stj¨arnan,och det l¨angsta avst˚andetfr˚an stj¨arnan. H¨arunders¨oker vi vilka m¨ojligaeccentriciteter som planeterna klarar av f¨oratt fortfarande holla sig stabila i systemet! Vi simulera systemet med olika eccentriciteter p˚aplaneterna och ser hur banorna evolverar. Det visar sig att m˚angaav de eccentriciteterna som os¨akerheten i parametrarna i v˚ardatabas till˚ater,rent sagt leder till kaotiska eller helt ostabila banor f¨orplaneterna. Vi har d¨arf¨orlyckats minska felet i parameterarna som beskriver HD 207832. Kan en habitabel planet befinna sig i HD 207832? Stj¨arnan,HD 207832, delar m˚angaegenskaper med v˚aransol n¨ardet kommer till dess storlek. Detta inneb¨aratt en habitabel planet, som liknar Jorden, skulle befinna sig p˚a ungef¨arsamma avst˚andfr˚anstj¨arnansom Jorden ¨arfr˚ansolen. Detta omr˚adetr˚akar vara precis mellan de tv˚aplaneterna vi k¨annertill i HD 207832. Fr˚agan¨arom den Jord-lika planeten klarar av att h˚allasig kvar i systemet mellan de tv˚agiganterna, utan att kastas ut p˚agrundav gravitationen som drar planeten mellan de andra himlakropparna. I detta projekt har vi i simuleringar satt in en tredje planet i systemet. Planeten ¨ar satt p˚aolika avst˚andfr˚anstj¨arnaninnom den beboeliga zonen runt HD 207832. I de flesta fallen klara sig den tredje planeten inte mellan de tv˚aJupiter-liknande planeterna. Den brukar allts˚akollidera eller utl¨osasfr˚ansytemet. Men det finns n˚agrafall, d¨arvi under vissa f¨oruts¨attningarkunnat beh˚alladen tredje planeten. Detta inneb¨aratt vi har hittat banor d¨aren beboelig planet skulle kunna befinna sig runt HD 207832. Acknowledgements This project has been a great experience and I would like to thank all the people who helped me to get where I am. Firstly, I want to thank Dr. Alexander James Mustill, who gave me the opportunity to take the project under his great supervision, and who introduced me to the tools used in planetary science. It was always exciting to bring my results to our meetings. Thank you for the great explanations, and for your great feedback and guidance. I also want to give my thanks to friends I spent so much time discussing with. You have been a great inspiration for my work. Lastly, I want to thank my parents and siblings, who motivated me all the way up to this point. Thanks for keeping up the contact. Especially thanks to Veronika, for always being there. Contents 1 Introduction 5 1.1 HD 207832 . .6 1.1.1 The Habitable Zone . .7 1.1.2 The Semi-Amplitude of a Low-Mass Planet . .8 1.2 The Orbital Elements . .8 1.2.1 The Conserved Quantities and Two Coordinates systems . .9 1.3 Planetary Evolution . 10 1.3.1 The Chaos in Planetary systems . 11 1.3.2 The Stability of Planetary systems . 12 1.3.3 The Hill Stability . 13 2 Method 15 2.1 The Hybrid Symplectic Integrator .................. 15 2.1.1 Working with Mercury6 ....................... 15 2.2 The Stability Analysis . 16 2.2.1 The Nominal System with Variable Eccentricities . 16 2.2.2 Exploring the Eccentricity Space . 17 2.2.3 The Analysis . 18 2.3 The Search for a Habitable Planet . 19 2.3.1 Simulating with Test Particle . 19 3 Results 21 3.1 Exploring the Eccentricity Space . 21 3.1.1 100 Myr Simulations . 23 3.2 The Possibility of a Habitable Planet . 24 4 Conclusions 26 4.1 The Eccentricity Space of HD 207832 . 26 4.2 The Level of Chaos . 27 4.3 The Habitable Planet . 27 A The Principle used in Mercury6 31 1 List of Figures 1.1 The nominal planetary system in HD 207832 (Haghighipour et al., 2012) and its habitable zone defined by the standard model (Kasting et al., 1993), with a radius between 0.85 AU and 1.65 AU. The inner and the outer planet are HD 207832b and HD 207832c respectively. .7 1.2 Some of the basic parameters used to describe a planetary orbit. The shad- owed area corresponds to the part of the orbit below a reference plane. The planet is moving in the direction of the arrow, away from the ascending node.9 1.3 The plot shows a time interval from a simulation of HD 207832, where the inner and the outer planet have the initial eccentricities 0.20 and 0.57 respectively. Notably, the amplitudes in the oscillations are found to be large. 11 1.4 The Fourier transform of the eccentricity for the outer planet in HD 207832. The simulations are for the nominal system but with the initial eccentricities, 0.40, for the inner planet, and 0.55, 0.56, and 0.57 for the outer planet respectively. The three systems are classified as fairly non-chaotic with a number of peaks in their power spectrum within [1-50), see Section 2.2.3. 12 1.5 The eccentricity space of the planet HD 207832c versus HD 207832b. The Hill stability limit divides the region where collisions between planets are allowed, from where they are not (Gladman, 1993). The parameters used for this plot can be found in Table 1.1 & 1.2. The nominal system with the eccentricities 0.13 and 0.27 for the respective planet, and the ellipses spanned by its upper one sigma and two sigma error bars, have been plotted. 14 2.1 The level of chaos is determined by the number of peaks that intersect the limit at 1% of the strongest peak.
Recommended publications
  • Using Kepler Systems to Constrain the Frequency and Severity of Dynamical Effects on Habitable Planets Alexander James Mustill Melvyn B
    Using Kepler systems to constrain the frequency and severity of dynamical effects on habitable planets Alexander James Mustill Melvyn B. Davies Anders Johansen Dynamical instability bad for habitability • Excitation of eccentricity can shift HZ or cause extreme seasons (Spiegel+10, Dressing+10) • Planets may be scattered out of HZ • Planet-planet collisions may remove biospheres, atmospheres, water • Earth-like planets may be eaten by Neptunes/Jupiters Strong dynamical effects: scattering and Kozai • Scattering: closely-spaced giant planets excite each others’ eccentricities (Chatterjee+08) • Kozai: inclined external perturber (e.g. binary) can cause very large eccentricity fluctuations (Kozai 62, Lidov 62, Naoz 16) Relevance of inner systems to HZ • If you can • form a hot Jupiter through high-eccentricity migration • damage a Kepler system at few tenths of an au • you will damage the habitable zone too Relevance of inner systems intrinsically • Large number of single-candidate systems found by Kepler relative to multiples • Is this left over from formation? Or do the multiples evolve into singles through dynamics? (Johansen+12) • Informs models of planet formation • all the Kepler systems are interestingly different to the Solar system, but do we have two interestingly different channels of planet formation or only one? What do we know about the prevalence of strong dynamical effects? • So far know little about planets in HZ • What we do know: • Violent dynamical history strong contender for hot Jupiter migration • Many giants have high
    [Show full text]
  • Lurking in the Shadows: Wide-Separation Gas Giants As Tracers of Planet Formation
    Lurking in the Shadows: Wide-Separation Gas Giants as Tracers of Planet Formation Thesis by Marta Levesque Bryan In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy CALIFORNIA INSTITUTE OF TECHNOLOGY Pasadena, California 2018 Defended May 1, 2018 ii © 2018 Marta Levesque Bryan ORCID: [0000-0002-6076-5967] All rights reserved iii ACKNOWLEDGEMENTS First and foremost I would like to thank Heather Knutson, who I had the great privilege of working with as my thesis advisor. Her encouragement, guidance, and perspective helped me navigate many a challenging problem, and my conversations with her were a consistent source of positivity and learning throughout my time at Caltech. I leave graduate school a better scientist and person for having her as a role model. Heather fostered a wonderfully positive and supportive environment for her students, giving us the space to explore and grow - I could not have asked for a better advisor or research experience. I would also like to thank Konstantin Batygin for enthusiastic and illuminating discussions that always left me more excited to explore the result at hand. Thank you as well to Dimitri Mawet for providing both expertise and contagious optimism for some of my latest direct imaging endeavors. Thank you to the rest of my thesis committee, namely Geoff Blake, Evan Kirby, and Chuck Steidel for their support, helpful conversations, and insightful questions. I am grateful to have had the opportunity to collaborate with Brendan Bowler. His talk at Caltech my second year of graduate school introduced me to an unexpected population of massive wide-separation planetary-mass companions, and lead to a long-running collaboration from which several of my thesis projects were born.
    [Show full text]
  • Dynamics of the Terrestrial Planets from a Large Number of N-Body Simulations ∗ Rebecca A
    Earth and Planetary Science Letters 392 (2014) 28–38 Contents lists available at ScienceDirect Earth and Planetary Science Letters www.elsevier.com/locate/epsl Dynamics of the terrestrial planets from a large number of N-body simulations ∗ Rebecca A. Fischer , Fred J. Ciesla Department of the Geophysical Sciences, University of Chicago, 5734 S Ellis Ave, Chicago, IL 60637, USA article info abstract Article history: The agglomeration of planetary embryos and planetesimals was the final stage of terrestrial planet Received 6 September 2013 formation. This process is modeled using N-body accretion simulations, whose outcomes are tested by Received in revised form 26 January 2014 comparing to observed physical and chemical Solar System properties. The outcomes of these simulations Accepted 3 February 2014 are stochastic, leading to a wide range of results, which makes it difficult at times to identify the full Availableonline25February2014 range of possible outcomes for a given dynamic environment. We ran fifty high-resolution simulations Editor: T. Elliott each with Jupiter and Saturn on circular or eccentric orbits, whereas most previous studies ran an Keywords: order of magnitude fewer. This allows us to better quantify the probabilities of matching various accretion observables, including low probability events such as Mars formation, and to search for correlations N-body simulations between properties. We produce many good Earth analogues, which provide information about the mass terrestrial planets evolution and provenance of the building blocks of the Earth. Most observables are weakly correlated Mars or uncorrelated, implying that individual evolutionary stages may reflect how the system evolved even late veneer if models do not reproduce all of the Solar System’s properties at the end.
    [Show full text]
  • Download This Article in PDF Format
    A&A 562, A92 (2014) Astronomy DOI: 10.1051/0004-6361/201321493 & c ESO 2014 Astrophysics Li depletion in solar analogues with exoplanets Extending the sample, E. Delgado Mena1,G.Israelian2,3, J. I. González Hernández2,3,S.G.Sousa1,2,4, A. Mortier1,4,N.C.Santos1,4, V. Zh. Adibekyan1, J. Fernandes5, R. Rebolo2,3,6,S.Udry7, and M. Mayor7 1 Centro de Astrofísica, Universidade do Porto, Rua das Estrelas, 4150-762 Porto, Portugal e-mail: [email protected] 2 Instituto de Astrofísica de Canarias, C/ Via Lactea s/n, 38200 La Laguna, Tenerife, Spain 3 Departamento de Astrofísica, Universidad de La Laguna, 38205 La Laguna, Tenerife, Spain 4 Departamento de Física e Astronomia, Faculdade de Ciências, Universidade do Porto, 4169-007 Porto, Portugal 5 CGUC, Department of Mathematics and Astronomical Observatory, University of Coimbra, 3049 Coimbra, Portugal 6 Consejo Superior de Investigaciones Científicas, CSIC, Spain 7 Observatoire de Genève, Université de Genève, 51 ch. des Maillettes, 1290 Sauverny, Switzerland Received 18 March 2013 / Accepted 25 November 2013 ABSTRACT Aims. We want to study the effects of the formation of planets and planetary systems on the atmospheric Li abundance of planet host stars. Methods. In this work we present new determinations of lithium abundances for 326 main sequence stars with and without planets in the Teff range 5600–5900 K. The 277 stars come from the HARPS sample, the remaining targets were observed with a variety of high-resolution spectrographs. Results. We confirm significant differences in the Li distribution of solar twins (Teff = T ± 80 K, log g = log g ± 0.2and[Fe/H] = [Fe/H] ±0.2): the full sample of planet host stars (22) shows Li average values lower than “single” stars with no detected planets (60).
    [Show full text]
  • Curriculum Vitae
    CURRICULUM VITAE Smadar Naoz September 2021 Contact University of California Los Angeles, Information Department of Physics & Astronomy 30 Portola Plaza, Box 951547 E-mail: [email protected] Los Angeles, CA 90095 WWW: http://www.astro.ucla.edu/∼snaoz/ Research Dynamics of planetary, stellar and black hole systems, which include formation of Hot Jupiters, Interests globular clusters, spiral structure, compact objects etc. Cosmology, structure formation in the early Universe, reionization and 21cm fluctuations. Education Tel Aviv University, Tel Aviv, Israel Ph.D. in Physics, January 2010 Hebrew University of Jerusalem, Jerusalem, Israel M.S. in Physics, Magna Cum Laude, 2004 B.S. in Physics 2002 Positions University of California, Los Angeles Associate professor since July 2019 Howard & Astrid Preston Term Chair in Astrophysics since July 2018 Assistant professor 2014-2019 Harvard Smithsonian CfA, Institute for Theory and Computation Einstein Fellow, September 2012 { June 2014 ITC Fellow, September 2011 { August 2012 Northwestern University, CIERA Gruber Fellow, September 2010 { August 2011 Postdoctoral associate in theoretical astrophysics, January 2010 { August 2010 Scholarships Helen B. Warner Prize, awarded by the American Astronomical Society, 2020 Honors and Scialog fellow, and accepted proposal, Signatures of Life in the Universe, 2020/2021 (conference Awards postponed to 2021 due to COVID-19) Career Commitment to Diversity, Equity and Inclusion Award, given by UCLA Academic Senate 2019. For other diversity awards, see xDEI. Hellman Fellows Award, awarded by Hellman Fellows Program, aimed to support the research of promising Assistant Professors who show capacity for great distinction in their research, June 2017 Multiple departmental teaching awards 2015-2019, see xTeaching, for details Sloan Research Fellowships awarded by the Alfred P.
    [Show full text]
  • Exoplanet.Eu Catalog Page 1 # Name Mass Star Name
    exoplanet.eu_catalog # name mass star_name star_distance star_mass OGLE-2016-BLG-1469L b 13.6 OGLE-2016-BLG-1469L 4500.0 0.048 11 Com b 19.4 11 Com 110.6 2.7 11 Oph b 21 11 Oph 145.0 0.0162 11 UMi b 10.5 11 UMi 119.5 1.8 14 And b 5.33 14 And 76.4 2.2 14 Her b 4.64 14 Her 18.1 0.9 16 Cyg B b 1.68 16 Cyg B 21.4 1.01 18 Del b 10.3 18 Del 73.1 2.3 1RXS 1609 b 14 1RXS1609 145.0 0.73 1SWASP J1407 b 20 1SWASP J1407 133.0 0.9 24 Sex b 1.99 24 Sex 74.8 1.54 24 Sex c 0.86 24 Sex 74.8 1.54 2M 0103-55 (AB) b 13 2M 0103-55 (AB) 47.2 0.4 2M 0122-24 b 20 2M 0122-24 36.0 0.4 2M 0219-39 b 13.9 2M 0219-39 39.4 0.11 2M 0441+23 b 7.5 2M 0441+23 140.0 0.02 2M 0746+20 b 30 2M 0746+20 12.2 0.12 2M 1207-39 24 2M 1207-39 52.4 0.025 2M 1207-39 b 4 2M 1207-39 52.4 0.025 2M 1938+46 b 1.9 2M 1938+46 0.6 2M 2140+16 b 20 2M 2140+16 25.0 0.08 2M 2206-20 b 30 2M 2206-20 26.7 0.13 2M 2236+4751 b 12.5 2M 2236+4751 63.0 0.6 2M J2126-81 b 13.3 TYC 9486-927-1 24.8 0.4 2MASS J11193254 AB 3.7 2MASS J11193254 AB 2MASS J1450-7841 A 40 2MASS J1450-7841 A 75.0 0.04 2MASS J1450-7841 B 40 2MASS J1450-7841 B 75.0 0.04 2MASS J2250+2325 b 30 2MASS J2250+2325 41.5 30 Ari B b 9.88 30 Ari B 39.4 1.22 38 Vir b 4.51 38 Vir 1.18 4 Uma b 7.1 4 Uma 78.5 1.234 42 Dra b 3.88 42 Dra 97.3 0.98 47 Uma b 2.53 47 Uma 14.0 1.03 47 Uma c 0.54 47 Uma 14.0 1.03 47 Uma d 1.64 47 Uma 14.0 1.03 51 Eri b 9.1 51 Eri 29.4 1.75 51 Peg b 0.47 51 Peg 14.7 1.11 55 Cnc b 0.84 55 Cnc 12.3 0.905 55 Cnc c 0.1784 55 Cnc 12.3 0.905 55 Cnc d 3.86 55 Cnc 12.3 0.905 55 Cnc e 0.02547 55 Cnc 12.3 0.905 55 Cnc f 0.1479 55
    [Show full text]
  • Dynamical Models of Terrestrial Planet Formation
    Dynamical Models of Terrestrial Planet Formation Jonathan I. Lunine, LPL, The University of Arizona, Tucson AZ USA, 85721. [email protected] David P. O’Brien, Planetary Science Institute, Tucson AZ USA 85719 Sean N. Raymond, CASA, University of Colorado, Boulder CO USA 80302 Alessandro Morbidelli, Obs. de la Coteˆ d’Azur, Nice, F-06304 France Thomas Quinn, Department of Astronomy, University of Washington, Seattle USA 98195 Amara L. Graps, SWRI, Boulder CO USA 80302 Revision submitted to Advanced Science Letters May 23, 2009 Abstract We review the problem of the formation of terrestrial planets, with particular emphasis on the interaction of dynamical and geochemical models. The lifetime of gas around stars in the process of formation is limited to a few million years based on astronomical observations, while isotopic dating of meteorites and the Earth-Moon system suggest that perhaps 50-100 million years were required for the assembly of the Earth. Therefore, much of the growth of the terrestrial planets in our own system is presumed to have taken place under largely gas-free conditions, and the physics of terrestrial planet formation is dominated by gravitational interactions and collisions. The ear- liest phase of terrestrial-planet formation involve the growth of km-sized or larger planetesimals from dust grains, followed by the accumulations of these planetesimals into ∼100 lunar- to Mars- mass bodies that are initially gravitationally isolated from one-another in a swarm of smaller plan- etesimals, but eventually grow to the point of significantly perturbing one-another. The mutual perturbations between the embryos, combined with gravitational stirring by Jupiter, lead to orbital crossings and collisions that drive the growth to Earth-sized planets on a timescale of 107 − 108 years.
    [Show full text]
  • Three-Body Capture of Irregular Satellites: Application to Jupiter
    Icarus 208 (2010) 824–836 Contents lists available at ScienceDirect Icarus journal homepage: www.elsevier.com/locate/icarus Three-body capture of irregular satellites: Application to Jupiter Catherine M. Philpott a,*, Douglas P. Hamilton a, Craig B. Agnor b a Department of Astronomy, University of Maryland, College Park, MD 20742-2421, USA b Astronomy Unit, School of Mathematical Sciences, Queen Mary University of London, London E14NS, UK article info abstract Article history: We investigate a new theory of the origin of the irregular satellites of the giant planets: capture of one Received 19 October 2009 member of a 100-km binary asteroid after tidal disruption. The energy loss from disruption is sufficient Revised 24 March 2010 for capture, but it cannot deliver the bodies directly to the observed orbits of the irregular satellites. Accepted 26 March 2010 Instead, the long-lived capture orbits subsequently evolve inward due to interactions with a tenuous cir- Available online 7 April 2010 cumplanetary gas disk. We focus on the capture by Jupiter, which, due to its large mass, provides a stringent test of our model. Keywords: We investigate the possible fates of disrupted bodies, the differences between prograde and retrograde Irregular satellites captures, and the effects of Callisto on captured objects. We make an impulse approximation and discuss Jupiter, Satellites Planetary dynamics how it allows us to generalize capture results from equal-mass binaries to binaries with arbitrary mass Satellites, Dynamics ratios. Jupiter We find that at Jupiter, binaries offer an increase of a factor of 10 in the capture rate of 100-km objects as compared to single bodies, for objects separated by tens of radii that approach the planet on relatively low-energy trajectories.
    [Show full text]
  • AMD-Stability and the Classification of Planetary Systems
    A&A 605, A72 (2017) DOI: 10.1051/0004-6361/201630022 Astronomy c ESO 2017 Astrophysics& AMD-stability and the classification of planetary systems? J. Laskar and A. C. Petit ASD/IMCCE, CNRS-UMR 8028, Observatoire de Paris, PSL, UPMC, 77 Avenue Denfert-Rochereau, 75014 Paris, France e-mail: [email protected] Received 7 November 2016 / Accepted 23 January 2017 ABSTRACT We present here in full detail the evolution of the angular momentum deficit (AMD) during collisions as it was described in Laskar (2000, Phys. Rev. Lett., 84, 3240). Since then, the AMD has been revealed to be a key parameter for the understanding of the outcome of planetary formation models. We define here the AMD-stability criterion that can be easily verified on a newly discovered planetary system. We show how AMD-stability can be used to establish a classification of the multiplanet systems in order to exhibit the planetary systems that are long-term stable because they are AMD-stable, and those that are AMD-unstable which then require some additional dynamical studies to conclude on their stability. The AMD-stability classification is applied to the 131 multiplanet systems from The Extrasolar Planet Encyclopaedia database for which the orbital elements are sufficiently well known. Key words. chaos – celestial mechanics – planets and satellites: dynamical evolution and stability – planets and satellites: formation – planets and satellites: general 1. Introduction motion resonances (MMR, Wisdom 1980; Deck et al. 2013; Ramos et al. 2015) could justify the Hill-type criteria, but the The increasing number of planetary systems has made it nec- results on the overlap of the MMR island are valid only for close essary to search for a possible classification of these planetary orbits and for short-term stability.
    [Show full text]
  • Exoplanet.Eu Catalog Page 1 Star Distance Star Name Star Mass
    exoplanet.eu_catalog star_distance star_name star_mass Planet name mass 1.3 Proxima Centauri 0.120 Proxima Cen b 0.004 1.3 alpha Cen B 0.934 alf Cen B b 0.004 2.3 WISE 0855-0714 WISE 0855-0714 6.000 2.6 Lalande 21185 0.460 Lalande 21185 b 0.012 3.2 eps Eridani 0.830 eps Eridani b 3.090 3.4 Ross 128 0.168 Ross 128 b 0.004 3.6 GJ 15 A 0.375 GJ 15 A b 0.017 3.6 YZ Cet 0.130 YZ Cet d 0.004 3.6 YZ Cet 0.130 YZ Cet c 0.003 3.6 YZ Cet 0.130 YZ Cet b 0.002 3.6 eps Ind A 0.762 eps Ind A b 2.710 3.7 tau Cet 0.783 tau Cet e 0.012 3.7 tau Cet 0.783 tau Cet f 0.012 3.7 tau Cet 0.783 tau Cet h 0.006 3.7 tau Cet 0.783 tau Cet g 0.006 3.8 GJ 273 0.290 GJ 273 b 0.009 3.8 GJ 273 0.290 GJ 273 c 0.004 3.9 Kapteyn's 0.281 Kapteyn's c 0.022 3.9 Kapteyn's 0.281 Kapteyn's b 0.015 4.3 Wolf 1061 0.250 Wolf 1061 d 0.024 4.3 Wolf 1061 0.250 Wolf 1061 c 0.011 4.3 Wolf 1061 0.250 Wolf 1061 b 0.006 4.5 GJ 687 0.413 GJ 687 b 0.058 4.5 GJ 674 0.350 GJ 674 b 0.040 4.7 GJ 876 0.334 GJ 876 b 1.938 4.7 GJ 876 0.334 GJ 876 c 0.856 4.7 GJ 876 0.334 GJ 876 e 0.045 4.7 GJ 876 0.334 GJ 876 d 0.022 4.9 GJ 832 0.450 GJ 832 b 0.689 4.9 GJ 832 0.450 GJ 832 c 0.016 5.9 GJ 570 ABC 0.802 GJ 570 D 42.500 6.0 SIMP0136+0933 SIMP0136+0933 12.700 6.1 HD 20794 0.813 HD 20794 e 0.015 6.1 HD 20794 0.813 HD 20794 d 0.011 6.1 HD 20794 0.813 HD 20794 b 0.009 6.2 GJ 581 0.310 GJ 581 b 0.050 6.2 GJ 581 0.310 GJ 581 c 0.017 6.2 GJ 581 0.310 GJ 581 e 0.006 6.5 GJ 625 0.300 GJ 625 b 0.010 6.6 HD 219134 HD 219134 h 0.280 6.6 HD 219134 HD 219134 e 0.200 6.6 HD 219134 HD 219134 d 0.067 6.6 HD 219134 HD
    [Show full text]
  • The Lick-Carnegie Survey: a New Two-Planet System Around the Star HD 207832
    Accepted for Publication in ApJ The Lick-Carnegie Survey: A New Two-Planet System Around the Star HD 207832 Nader Haghighipour1, R. Paul Butler2, Eugenio J. Rivera3, Gregory W. Henry4, and Steven S. Vogt3, ABSTRACT Keck/HIRES precision radial velocities of HD 207832 indicate the presence of two Jovian-type planetary companions in Keplerian orbits around this G star. The planets have minimum masses of M sin i = 0.56 MJup and 0.73 MJup, with orbital periods of ∼ 162 and ∼ 1156 days, and eccentricities of 0.13 and 0.27, respectively. Str¨omgren b and y photometry reveals a clear stellar rotation sig- nature of the host star with a period of 17.8 days, well separated from the period of the radial velocity variations, reinforcing their Keplerian origin. The values of the semimajor axes of the planets suggest that these objects have migrated from the region of giant planet formation to closer orbits. In order to examine the possibility of the existence of additional (small) planets in the system, we studied the orbital stability of hypothetical terrestrial-sized objects in the region between the two planets and interior to the orbit of the inner body. Results indi- cated that stable orbits exist only in a small region interior to planet b. However, the current observational data offer no evidence for the existence of additional objects in this system. Subject headings: stars: individual: HD 207832 – stars: planetary systems arXiv:1207.2806v1 [astro-ph.EP] 11 Jul 2012 1Institute for Astronomy and NASA Astrobiology Institute, University of Hawaii-Manoa, Honolulu, HI 96822 2Department of Terrestrial Magnetism, Carnegie Institute of Washington, Washington, DC 20015 3UCO/Lick Observatory, Department of Astronomy and Astrophysics, University of California at Santa Cruz, Santa Cruz, CA 95064 4Center of Excellence in Information Systems, Tennessee State University, Nashville, TN 37209 –2– 1.
    [Show full text]
  • The Photoeccentric Effect and Proto-Hot Jupiters. I
    The Astrophysical Journal, 756:122 (13pp), 2012 September 10 doi:10.1088/0004-637X/756/2/122 C 2012. The American Astronomical Society. All rights reserved. Printed in the U.S.A. THE PHOTOECCENTRIC EFFECT AND PROTO-HOT JUPITERS. I. MEASURING PHOTOMETRIC ECCENTRICITIES OF INDIVIDUAL TRANSITING PLANETS Rebekah I. Dawson1 and John Asher Johnson2,3 1 Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS-10, Cambridge, MA 02138, USA; [email protected] 2 Department of Astronomy, California Institute of Technology, 1200 East California Boulevard, MC 249-17, Pasadena, CA 91125, USA 3 NASA Exoplanet Science Institute (NExScI), CIT Mail Code 100-22, 770 South Wilson Avenue, Pasadena, CA 91125, USA Received 2012 April 5; accepted 2012 July 9; published 2012 August 21 ABSTRACT Exoplanet orbital eccentricities offer valuable clues about the history of planetary systems. Eccentric, Jupiter-sized planets are particularly interesting: they may link the “cold” Jupiters beyond the ice line to close-in hot Jupiters, which are unlikely to have formed in situ. To date, eccentricities of individual transiting planets primarily come from radial-velocity measurements. Kepler has discovered hundreds of transiting Jupiters spanning a range of periods, but the faintness of the host stars precludes radial-velocity follow-up of most. Here, we demonstrate a Bayesian method of measuring an individual planet’s eccentricity solely from its transit light curve using prior knowledge of its host star’s density. We show that eccentric Jupiters are readily identified by their short ingress/ egress/total transit durations—part of the “photoeccentric” light curve signature of a planet’s eccentricity—even with long-cadence Kepler photometry and loosely constrained stellar parameters.
    [Show full text]