Plasma and Magnetic Field Parameters in the Vicinity of Short-periodic Giant Exoplanets

Details Plasma and Magnetic Field Parameters in the Vicinity of Short-periodic Giant Exoplanets Plasma and Magnetic Field Parameters in the Vicinity of Short-periodic Giant Exoplanets

Apr 2005

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2005apjs..157..396e&link_type=abstract

The Astrophysical Journal Supplement Series, Volume 157, Issue 2, pp. 396-401.

Astronomy and Astrophysics

Astronomy

19

Magnetic Fields, Stars: Planetary Systems, Plasmas, Shock Waves, Stars: Winds, Outflows

Scientific paper

During the past years, more than 130 giant planets were discovered in extrasolar planetary systems. Because of the fact that the orbital distances are very close to their host stars, these planets are embedded in a dense stellar wind, which can pick up planetary ions. We model the stellar wind interaction of the short-periodic exoplanets OGLE-TR-56b and HD 209458b at their orbital distances of ~0.023 AU and ~0.045 AU, by calculating the Alfvén Mach number and the magnetosonic Mach number in the stellar wind plasma flow. We then analyze the different plasma interaction regimes around the planetary obstacles, which appear for different stellar wind parameters. Our study shows that the stellar wind plasma parameters like temperature, interplanetary magnetic field, particle density, and velocity near planetary obstacles at orbital distances closer than 0.1-0.2 AU have conditions such that no bow shocks evolve. Our study shows also that these close-in exoplanets are in a submagnetosonic regime comparable to the magnetospheric plasma interaction of the inner satellites of Jupiter and Saturn. Furthermore, we compare the results achieved for both exoplanets with the Jupiter-class exoplanet HD 28185b at its orbital distance of ~1.03 AU. Finally, we also discuss the behavior of the stellar wind plasma flow close to the planetary obstacles of two highly eccentric gas giants, namely, HD 108147b and HD 162020b. Because of their eccentric orbits, these two exoplanets periodically experience both regimes with and without a bow shock. Finally, we simulate the neutral gas density of HD 209458b with a Monte Carlo model. By using the plasma parameters obtained in our study we calculate the ion production and loss rate of H+ with a test particle model. Our simulations yield H+ loss rates for HD 209458b or similar giant exoplanets in orders of about 108-109 g s-1. These ion loss rates are at least 1 order of magnitude lower than the observed loss rate of evaporating neutral H atoms. Our study indicates, that similar gas giants at larger orbital distances have lower ion loss rates. Thus, the dominating component of particle loss of short-periodic Jupiter-class exoplanets will be neutral hydrogen.

Affiliated with

Also associated with

No associations

Rating

Plasma and Magnetic Field Parameters in the Vicinity of Short-periodic Giant Exoplanets does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Plasma and Magnetic Field Parameters in the Vicinity of Short-periodic Giant Exoplanets, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Plasma and Magnetic Field Parameters in the Vicinity of Short-periodic Giant Exoplanets will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1454407