Astrophysics and Space Science Library 441 Ivan I. Shevchenko The Lidov-Kozai Effect – Applications in Exoplanet Research and Dynamical Astronomy The Lidov-Kozai Effect – Applications in Exoplanet Research and Dynamical Astronomy Astrophysics and Space Science Library EDITORIAL BOARD Chairman W.B.BURTON,NationalRadioAstronomyObservatory,Charlottesville, Virginia,U.S.A.([email protected]);UniversityofLeiden,TheNetherlands ([email protected]) F.BERTOLA,UniversityofPadua,Italy C.J.CESARSKY,CommissionforAtomicEnergy,Saclay,France P.EHRENFREUND,LeidenUniversity,TheNetherlands O.ENGVOLD,UniversityofOslo,Norway A.HECK,StrasbourgAstronomicalObservatory,France E.P.J.VANDENHEUVEL,UniversityofAmsterdam,TheNetherlands V.M.KASPI,McGillUniversity,Montreal,Canada J.M.E.KUIJPERS,UniversityofNijmegen,TheNetherlands H.VANDERLAAN,UniversityofUtrecht,TheNetherlands P.G.MURDIN,InstituteofAstronomy,Cambridge,UK B.V.SOMOV,AstronomicalInstitute,MoscowStateUniversity,Russia R.A.SUNYAEV,SpaceResearchInstitute,Moscow,Russia Moreinformationaboutthisseriesathttp://www.springer.com/series/5664 Ivan I. Shevchenko The Lidov-Kozai Effect – Applications in Exoplanet Research and Dynamical Astronomy 123 IvanI.Shevchenko PulkovoObservatoryoftheRussian AcademyofSciences St.Petersburg,Russia ISSN0067-0057 ISSN2214-7985 (electronic) AstrophysicsandSpaceScienceLibrary ISBN978-3-319-43520-6 ISBN978-3-319-43522-0 (eBook) DOI10.1007/978-3-319-43522-0 LibraryofCongressControlNumber:2016951301 ©SpringerInternationalPublishingSwitzerland2017 Thisworkissubjecttocopyright.AllrightsarereservedbythePublisher,whetherthewholeorpartof thematerialisconcerned,specificallytherightsoftranslation,reprinting,reuseofillustrations,recitation, broadcasting,reproductiononmicrofilmsorinanyotherphysicalway,andtransmissionorinformation storageandretrieval,electronicadaptation,computersoftware,orbysimilarordissimilarmethodology nowknownorhereafterdeveloped. Theuseofgeneraldescriptivenames,registerednames,trademarks,servicemarks,etc.inthispublication doesnotimply,evenintheabsenceofaspecificstatement,thatsuchnamesareexemptfromtherelevant protectivelawsandregulationsandthereforefreeforgeneraluse. Thepublisher,theauthorsandtheeditorsaresafetoassumethattheadviceandinformationinthisbook arebelievedtobetrueandaccurateatthedateofpublication.Neitherthepublishernortheauthorsor theeditorsgiveawarranty,expressorimplied,withrespecttothematerialcontainedhereinorforany errorsoromissionsthatmayhavebeenmade. Coverillustration:Anexoplanetseenfromitsmoon(artist’simpression).Credit:IAU/L.Calçada Printedonacid-freepaper ThisSpringerimprintispublishedbySpringerNature TheregisteredcompanyisSpringerInternationalPublishingAGSwitzerland Preface Uptonow,itnearlymakesmelaughandcryofrapturewhenI recallthisresult. VladimirBeletsky,SixDozens(Memoirs) The Lidov-Kozai effect (LKE), as any other basic astrophysical phenomena, has several “faces”, or manifestations. The most familiar face, granted in Wikipedia, isthephenomenonofcoupledperiodicvariations(whichcanbeverylarge)ofthe inclination and eccentricity of an orbiting body, which (the variations) may take placeinthepresenceofaninclined-enoughperturber. Aface,lessfamiliartothegeneralaudience,butphysicallythegenericone,isthe so-called phenomenonof !-libration; i.e., libration of the argument of pericenter of an orbiting body,when an inclined-enoughperturberis present. In fact, the !- librationisatthecoreoftheLKE:itisjustalarge-amplitude!-librationthatentails thementionedcoupledvariationsininclinationandeccentricity. Anotherconcept,frequentlypresentinthemodernastrophysicalliterature,isthe LKEasavaluabletooltoexplainvariousmergerevents.Indeed,ifitis“necessary to merge”anygravitatingbinary(saya binaryconsistingoftwo ordinarystars, or black holes, or asteroids, or a star and a “hotJupiter,” or a planetand an artificial satellite,etc.)intoasingleobject,theLKEiscommonlythefirstoneinthequeue of possible explaining mechanisms that come to mind of an astrophysicist. This is just because it is rapid and no dissipation is needed—only the presence of a perturber.This third face revealed itself already in the pioneeringworks of Lidov (whooutlinedaconditionforamergerofasatellitewiththeEarth,inparticularthe Moon with the Earth), and since then it has been becoming only more and more attractiveforresearchers. To date, the LKE,in all ofthese faces, hasbeenverifiedto be importantin the dynamics of a lot of kinds of astrophysical objects. Historically the applications started with satellites and asteroids; now they comprise comets, trans-Neptunian objects, exoplanets, multiple stars, and many others. Perhaps, of most interest for theastronomicalandastrophysicalcommunityatpresentisitsrelevanceformany exoplanetarysystems. RecentyearswitnessedmajoradvancementsinthetheoryofLKE.Inparticular, anotherfaceoftheLKEemerged:theso-calledflip(orbitturnover)phenomenon. ItwouldbenoexaggerationtosaythatatpresenttheLidov-Kozaieffectbecomes oneof themoststudied astrophysicaleffects;this ismanifested,in particular,in a v vi Preface sharpriseofcitationsofthepioneerarticlesofLidovandKozaiduringrecentyears (seeFig.1). Fig.1 Theper-yearnumberofcitationsofthepioneerarticlesofLidovandKozai,asafunction oftime,uptoyear2015inclusive(ThecitationdataoftheNASAADSdatabasehavebeenused toconstructthediagram) Thetopics,coveredinthisbook,include:historicalbackgroundforappearance of works by Lidov and Kozai in the beginning of the 1960s (Luna-3, etc.); modern secular theories and integrable approximationsin celestial mechanics; an overview of classical works on the Lidov-Kozai effect; modern advancements and generalizations in the Lidov-Kozai theory, in particular in the framework of noncircularandnonrestrictedproblems;theLidov-Kozaimechanismexplainingthe observedorbitalconfigurationsofirregularsatellites,explainingcomets-sungrazers, andexplainingtheobserveddynamicalpatternsintheasteroidandKuiperbelts;the role of the Lidov-Kozai mechanism (in particular the Lidov-Kozai migration) in sculptingexoplanetarysystems;applicationsinstellardynamics,suchasscenarios for formation of close binary stars; and explanations for highly eccentric stellar orbitsintheGalacticcenter. Theinitialaimofthisbookwastoprovidethemostfullcoverageoftheeffect’s theoryandapplications.However,duetoalargeamountofthepublishedandnewly appearing advancements, it is practically impossible to fulfill this aim in detail. Therefore,apartfromtheprovidedbibliography,forfurtherreadingonthesubject, IwouldrecommendthematerialontheLidov-Kozaieffectinasteroidaldynamics, presented in Sects.8.2 and 11.2.2 of the book Modern Celestial Mechanics by A. Morbidelli (2002), and the material on the LKE in exoplanetary dynamics presented in Sects.7 and 8 of the review “The Long-Term Dynamical Evolution ofPlanetarySystems”byM.B.Daviesetal.(2014). Preface vii Thepresentedbookisself-contained:onlybasicknowledgeinmathematicsand mechanicsisrequiredforunderstandingthematerial,ifreadfromthebeginning.I hopethatthebookcanbehelpfulforaresearcherworkinginastrophysics,celestial mechanics, stellar dynamics, theoretical mechanics, and space mission design, at any level (researcher, graduate student, undergraduate student), depending on the interestsofthereader. I am mostgratefulto Vladislav Sidorenko,KonstantinKholshevnikov,Mikhail Vashkovyak, and Alessandro Morbidelli for valuable remarks and comments. I am especially thankful to Vladislav Sidorenko for providing rare bibliographic materialsonthesubject. SaintPetersburg,Russia IvanI.Shevchenko 2016 Contents 1 DynamicalEssenceandHistoricalBackground.......................... 1 1.1 TheKeplerianOrbitalElements........................................ 2 1.2 The“omega-libration”.................................................. 5 1.3 TheBreakthroughPremises ............................................ 6 1.4 FromLuna-3toModernSpaceMissions.............................. 9 2 AveragingandNormalizationinCelestialMechanics ................... 13 2.1 TheHamiltonianFormalism............................................ 14 2.2 TheTwo-BodyProbleminaHamiltonianForm ...................... 15 2.3 AnN-BodyProbleminaHamiltonianForm.......................... 16 2.4 TheDelaunayVariables................................................. 17 2.5 Near-IntegrableSystems................................................ 19 2.6 ThevonZeipelMethod................................................. 20 2.7 TheHori–DepritMethod ............................................... 23 3 ClassicalResults.............................................................. 27 3.1 ASingle-AveragedR3BP............................................... 28 3.2 TheDouble-AveragedR3BP ........................................... 31 3.2.1 TheLidov-KozaiHamiltonian ................................. 31 3.2.2 EquationsandConstantsofMotion............................ 34 3.2.3 ClassificationofOrbits......................................... 36 3.2.4 TheLidov-KozaiDiagrams .................................... 39 3.2.5 TheSolutionintheJacobiEllipticFunctions ................. 41 3.3 LKE-PreventingPhenomena ........................................... 46 3.3.1 PerturbationsbyAdditionalOrbitingBodies.................. 47 3.3.2 Primary’sOblateness........................................... 48 3.3.3 Tides............................................................. 50 3.3.4 GeneralRelativity .............................................. 52 3.3.5 TheOrbitalPrecessioninTotal ................................ 53 3.4 CriticalRadii............................................................ 54 ix