CI Tau: A controlled experiment in disk-planet interaction

TL;DR

This study uses hydrodynamic simulations and radiative transfer modeling to reconcile the presence of a massive planet close to the star with the observed disk properties of CI Tau, suggesting that hot Jupiters may not create clear disk gaps.

Contribution

The paper demonstrates through simulations that a massive planet at 0.1 au does not significantly alter the disk's near-infrared excess, challenging previous assumptions about planet-induced disk gaps.

Findings

Massive planets at 0.1 au have little impact on near-infrared excess.

Observed SEDs are consistent with the presence of CI Tau b.

Transition-disk signatures may indicate nascent warm Jupiters at around 1 AU.

Abstract

CI Tau is a young (~2 Myr) T Tauri system with a substantial near-infrared excess in its SED, indicating that the protoplanetary disk extends very close to its star. This is seemingly at odds with the radial-velocity discovery of CI Tau b, a ~12 MJ planet at ~0.1 au, which would be expected to carve a wide, deep cavity in the innermost disk. To investigate this apparent contradiction, we run 2D hydrodynamics simulations to study the effect of the planet on the disk, then post-process the results with radiative transfer to obtain an SED. We find that at ~0.1 au, even such a massive companion has little impact on the near-infrared excess, a result that holds regardless of planetary eccentricity and dust size distribution. Conversely, the observed full-disk signature in CI Tau's SED is consistent with the existence of the hot super-Jupiter CI Tau b. As our simulations uncover, clear transition-disk signatures in SEDs are more likely to be signposts of nascent "warm" Jupiters, located at around 1 AU in the future habitable zones of their host stars.