Dynamics of tidally captured planets in the Galactic Center
  Recent observations suggest ongoing planet formation in the innermost parsec
of the Galactic center (GC). The super-massive black hole (SMBH) might strip
planets or planetary embryos from their parent star, bringing them close enough
to be tidally disrupted. Photoevaporation by the ultraviolet field of young
stars, combined with ongoing tidal disruption, could enhance the near-infrared
luminosity of such starless planets, making their detection possible even with
current facilities. In this paper, we investigate the chance of planet tidal
captures by means of high-accuracy N-body simulations exploiting Mikkola's
algorithmic regularization. We consider both planets lying in the clockwise
(CW) disk and planets initially bound to the S-stars. We show that tidally
captured planets remain on orbits close to those of their parent star.
Moreover, the semi-major axis of the planet orbit can be predicted by simple
analytic assumptions in the case of prograde orbits. We find that starless
planets that were initially bound to CW disk stars have mild eccentricities and
tend to remain in the CW disk. However, we speculate that angular momentum
diffusion and scattering with other young stars in the CW disk might bring
starless planets on low-angular momentum orbits. In contrast, planets initially
bound to S-stars are captured by the SMBH on highly eccentric orbits, matching
the orbital properties of the G1 and G2 clouds. Our predictions apply not only
to planets but also to low-mass stars initially bound to the S-stars and
tidally captured by the SMBH.
