Sunday, July 31, 2016

Planets Captured by the Supermassive Black Hole

G2 is a dusty object in a highly eccentric orbit around the supermassive black hole in the center of the Milky Way galaxy. At closest approach, G2 is only ~200 AU from the supermassive black hole. G2 could be a low-mass star hosting a protoplanetary disk or a planet that was captured by the supermassive black hole. Trani et al. (2016) ran 10,000 simulations of a three-body hierarchical system comprised of a supermassive black hole, a star and a planet initially in a bound orbit around the star.

The simulations show that the planet can be removed from its host star and be captured into an independent orbit around the supermassive black hole. However, none of the simulated planets can achieve a highly eccentric orbit around the supermassive black hole. The smallest closest approach distance is 1750 AU, roughly 9 times larger than the closest approach distance of G2. Nevertheless, perturbations from other stars around the supermassive back hole can potentially perturb planets into highly eccentric orbits similar to the orbit of G2.

Trani et al. (2016), "Dynamics of tidally captured planets in the Galactic Center", arXiv:1607.07438v1 [astro-ph.GA]