CI Tau is currently the only T Tauri star with an inner protoplanetary disk
that hosts a planet, CI Tau b, that has been detected by a radial velocity
survey. This provides the unique opportunity to study disk features that were
imprinted by that planet. We present multi-epoch spectroscopic data, taken with
NASA IRTF in 2022, of the 12CO and hydrogen Pfβ line emissions
spanning 9 consecutive nights, which is the proposed orbital period of CI Tau
b. We find that the star's accretion rate varied according to that 9~d period,
indicative of companion driven accretion. Analysis of the 12CO emission
lines reveals that the disk can be described with an inner and outer component
spanning orbital radii 0.05-0.13~au and 0.15-1.5~au, respectively. Both
components have eccentricities of about 0.05 and arguments of periapses that
are oppositely aligned. We present a proof-of-concept hydrodynamic simulation
that shows a massive companion on a similarly eccentric orbit can recreate a
similar disk structure. Our results allude to such a companion being located
around an orbital distance of 0.14~au. However, this planet's orbital
parameters may be inconsistent with those of CI Tau b whose high eccentricity
is likely not compatible with the low disk eccentricities inferred by our
model.Comment: Accepted to A