Seminars

Lecturer: Melanie Köhler (Institut für Planetologie, WWU Münster)
Date: 2005-08-04 10:00
Place: Aniara

Dust around Main-Sequence Stars

Dust particles are an important component of the small bodies of our planetary system. Investigating the orbits and properties of the dust helps to understand the evolution of the small bodies. In a similar way dust as well as the small bodies exist in the planetary systems around other stars. Due to their large surface area compared to their mass, dust particles are easily observed and allow for studies of the evolving planetary systems.

These dust grains are influenced by forces and effects, which determine their dynamical behaviour and the size distribution in the circumstellar dust disk. Particles can be ejected from a dust disk due to radiation pressure force. The radiation pressure force furthermore influences the particles in bound orbits, which are decelerated and spiral towards the central star. This effect is known as the Poynting- Robertson effect. The influence of the radiation pressure force depends on the properties of the dust grains as well as on the temperature of the central star.

We present model calculations of the radiation pressure force where we consider spherical and porous particles of different materials. The influence of the radiation pressure force is stronger on big aggregates than on spherical grains. Moreover the influence of the radiation pressure decreases with an increasing transparency of the dust.

Created 2005-08-10 17:17:12 by Rick McGregor
Last changed 2005-08-10 17:17:12 by Rick McGregor