Collisions of Free-floating Planets with Evolved Stars in Globular Clusters
Abstract
We estimate the rate of collisions between stars and free-floating planets (FFPs) in globular clusters, in particular, the collision of FFPs with red giant branch (RGB) stars. Recent dynamical simulations imply that the density of such objects could exceed ~106 pc-3 near the cores of rich globular clusters. We show that in these clusters ~5%-10% of all RGB stars near the core would suffer a collision with an FFP and that such a collision can spin up the RGB star's envelope by an order of magnitude. In turn, the higher rotation rates may lead to enhanced mass-loss rates on the RGB, which could result in bluer horizontal branch (HB) stars. Hence, it is plausible that the presence of a large population of FFPs in a globular cluster can influence the distribution of stars on the HB of that cluster to a detectable degree.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- December 2001
- DOI:
- 10.1086/338501
- arXiv:
- arXiv:astro-ph/0111210
- Bibcode:
- 2001ApJ...563L..87S
- Keywords:
-
- Galaxy: Globular Clusters: General;
- Stars: Planetary Systems;
- Stars: General;
- Stars: Horizontal-Branch;
- Stars: Mass Loss;
- Stars: Rotation;
- Astrophysics
- E-Print:
- 10 pages, Accepted by ApJ Letters