On the exospheres of the rocky planets HD219134b and c
Abstract
The large-scale magnetic field of the star HD219134 can be described as a dipole whose axis is roughly perpendicular to the stellar rotation axis. The stellar wind of HD219134 is highly non-axisymmetric, which implies that planets orbiting in the equatorial plane of the star interact with low and high speed winds in a very short timescale. The simulations show that sputtering processes release refractory elements from the entire dayside surface with velocities sufficiently high to allow for elongated trajectories of the sputtered particles. We find that oxygen and magnesium are expected to form an extended neutral exosphere. Because of the close proximity of both planets to the host star, a substantial amount of the neutral atoms will quickly be ionised and picked up by the stellar wind.
- Publication:
-
European Planetary Science Congress
- Pub Date:
- September 2018
- Bibcode:
- 2018EPSC...12.1149L