Project archive

It is a natural desire of astronomers to find planetary systems similar to the Solar System in which we live - but instead, they often see something very different, and totally unexpected. ESA's Herschel space observatory has now found six Sun-like stars that are surrounded by mysterious cold dusty belts, different from everything known previously.

The nearby star epsilon Eridani hosts one known inner planet, an outer Kuiper belt analog, and an inner disk of warm dust. Spitzer/IRS measurements indicate that warm dust is present at distances as small as a few AU from the star. We tested the hypothesis that the observed warm dust is generated by collisions in the outer belt and is transported inward by Poynting-Robertson drag and strong stellar winds...

The Edgeworth-Kuiper debris disk is (obviously) the nearest debris disk known. Like in all other debris disks large planetesimals produce dust in mutual collisions. The big difference to extrasolar Kuiper belts is that we actually can see the planetesimals. More than 1250 objects have been discovered up to now. Of course a lot more should be there...

Debris disks are dusty disks that surround main-sequence stars. What is actually observed is the thermal emission of dust, which is produced in frequent collisions between star-orbiting planetesimals. The latter are small bodies that must have accreted at early epochs and survived possible planet formation processes. The planetesimals around a star are typically grouped in one or several belts, similar to the Kuiper belt and asteroid belt in the solar system...

The long-term evolution of a debris disc is shown to be dominated by the slow transition of the population of planetesimals from the size distribution set at their growth phase to the steady-state size distribution defined by disruptive collisions. This transition is crucial for the temporal evolution of the observable dust masses and luminosities and for the deduced total disc masses. The developed models are compatible with observational statistics from the Spitzer Space Telescope surveys...

Observations have revealed a large variety of structures (global asymmetries, warps, belts, rings) and dynamical phenomena ("falling-evaporating bodies" or FEBs, the "β-Pic dust stream") in the disc of β Pictoris, most of which may indicate the presence of one or more planets orbiting the star...

The subject of the project has been models of the size distribution and the spatial distribution of the material in so-called debris discs around main-sequence stars. Thesediscs, which are considered as remnants of the formation of planetary systems, are ensembles of objects from sub-micron-sized dust to planetesimals with diameters up to hundreds of kilometres...

This project considers theoretical models of circumstellar debris discs. The main focus is the combination of mean motion resonances between a planet and circumstellar small bodies, which create structures, and collisions among the small bodies, which smear the structures out...