糖心TV

Astronomy Seminar

Speaker: Amy Bonsor - IPAG, Grenoble

Title: Scattering in Planetary Systems

The number of planet detections is increasing rapidly, but this is not the only way to learn about planetary systems. Interactions between small bodies and planets are critically important. I present two sets of observations where the scattering of smaller, cometary or asteroidal bodies, by planets may be able to explain the dust observed in locations where it cannot survive on long timescales. Around main sequence stars there are >30 examples of exozodiacal dust, composed of smlal dust grains observed within ~5AU of the star. Some of these stars also have outer belts and/or planets. The small dust should have a lifetime of less than a year. I hypothesise that the dust could be explained by a dynamical link between the outer belt and the exozodi. A similar scenario could also explain white dwarfs observed with dust discs and/or metal pollution. Comets or asteroids in an outer belt that surives the star's evolution are scattered inwards, potentially polluting the white dwarfs.