Quick search Find article
Quick search
Find article

FALLING TRANSITING EXTRASOLAR GIANT PLANETS

FREE ISSUE

B. Levrard1, C. Winisdoerffer and G. Chabrier

Show affiliations


We revisit the tidal stability of extrasolar systems harboring a transiting planet and demonstrate that, independently of any tidal model, none, but one (HAT-P-2b) of these planets has a tidal equilibrium state, which implies ultimately a collision of these objects with their host star. Consequently, conventional circularization and synchronization timescales cannot be defined because the corresponding states do not represent the endpoint of the tidal evolution. Using numerical simulations of the coupled tidal equations for the spin and orbital parameters of each transiting planetary system, we confirm these predictions and show that the orbital eccentricity and the stellar obliquity do not follow the usually assumed exponential relaxation but instead decrease significantly, eventually reaching a zero value only during the final runaway merging of the planet with the star. The only characteristic evolution timescale of all rotational and orbital parameters is the lifetime of the system, which crucially depends on the magnitude of tidal dissipation within the star. These results imply that the nearly circular orbits of transiting planets and the alignment between the stellar spin axis and the planetary orbit are unlikely to be due to tidal dissipation. Other dissipative mechanisms, for instance interactions with the protoplanetary disk, must be invoked to explain these properties.


Keywords

celestial mechanics; planetary systems: formation; planetary systems: protoplanetary disks


PACS

97.82.Fs Substellar companions; planets

97.10.Cv Stellar structure, interiors, evolution, nucleosynthesis, ages

97.10.Kc Stellar rotation

97.10.Fy Circumstellar shells, clouds, and expanding envelopes; circumstellar masers

Subjects

Astrophysics and astroparticles

Dates

Issue 1 (2009 February 10)

Received 2008 August 18, accepted for publication 2008 December 11

Published 2009 January 21



  1. Falling Transiting Extrasolar Giant Planets

    B. Levrard et al 2009 ApJ 692 L9

  2. Understanding the fate of merging supermassive black holes

    Manuela Campanelli 2005 Class. Quantum Grav. 22 S387

  3. Parallel heat flux limits in the tokamak scrape-off layer

    W Fundamenski 2005 Plasma Phys. Control. Fusion 47 R163

  4. Plasma, presheath, collisional sheath and collisionless sheath potential profiles in weakly ionized, weakly collisional plasma

    L Oksuz and N Hershkowitz 2005 Plasma Sources Sci. Technol. 14 201

  5. Hydrogen sulfide induces apoptosis in epithelial cells derived from human gingiva

    T Murata et al 2008 J. Breath Res. 2 017007

  6. Solutions of the Yang-Baxter equation for isotropic quantum spin chains

    T Kennedy 1992 J. Phys. A: Math. Gen. 25 2809

  7. Non-positive matrix elements for Hamiltonians of spin-1 chains

    T Kennedy 1994 J. Phys.: Condens. Matter 6 8015

  8. Exact diagonalisations of open spin-1 chains

    T Kennedy 1990 J. Phys.: Condens. Matter 2 5737

  9. Theory and phenomenology of vector mesons in medium

    Ralf Rapp 2007 J. Phys. G: Nucl. Part. Phys. 34 S405

  10. Electrical characterization of nanowire bridges incorporating biomolecular recognition elements

    Lu Shang et al 2005 Nanotechnology 16 2846

Related review articles

What's this?
View review articles related to this research to gain an insight into the key trends in this subject area. Related review articles are selected based on PACS/MSC codes, and are no more than three years old.

  1. The physical properties of extra-solar planets

View by subject




Export








Please login to access our web services, or create an account if you don't yet have one.

You must have cookies enabled in your web browser to be able to login.

Username
Password

Forgotten your password? Get a new one here.