The origin of the eccentricity of the hot Jupiter in CI Tau

Abstract

Following the recent discovery of the first radial velocity planet in a star still possessing a protoplanetary disc (CI Tau), we examine the origin of the planet's eccentricity (e $\sim 0.3$). We show through long timescale ($10^5$ orbits) simulations that the planetary eccentricity can be pumped by the disc, even when its local surface density is well below the threshold previously derived from short timescale integrations. We show that the disc may be able to excite the planet's orbital eccentricity in $<$ a Myr for the system parameters of CI Tau. We also perform two planet scattering experiments and show that alternatively the observed planet may plausibly have acquired its eccentricity through dynamical scattering of a migrating lower mass planet, which has either been ejected from the system or swallowed by the central star. In the latter case the present location and eccentricity of the observed planet can be recovered if it was previously stalled within the disc's magnetospheric cavity.

5 pages, 4 figures. Accepted to MNRAS letters

References in corpus (10)

• Direct Imaging of Multiple Planets Orbiting the Star HR 8799
• On the tidal evolution of Hot Jupiters on inclined orbits
• The Migration of Gap-Opening Planets is not Locked to Viscous Disk Evolution
• Migration of massive planets in accreting disks
• On the evolution of eccentric and inclined protoplanets embedded in protoplanetary disks
• The masses of young stars: CN as a probe of dynamical masses
• Magnetospheric Gap and Accumulation of Giant Planets Close to the Star
• Astrometric and photometric monitoring of GQ Lup and its sub-stellar companion
• Evolution of eccentricity and orbital inclination of migrating planets in 2:1 mean motion resonance
• Why are there so few hot Jupiters?

Cited by in corpus (6)

• Secular evolution of eccentricity in protoplanetary discs with gap-opening planets
• Hamiltonian hydrodynamics of eccentric discs
• On the Dust Signatures Induced by Eccentric Super-Earths in Protoplanetary Disks
• Focusing of nonlinear eccentric waves in astrophysical discs
• Estimating the depth of gaps opened by planets in eccentric orbit
• Focusing of nonlinear eccentric waves in astrophysical discs. II. Excitation and damping of tightly-wound waves