Universe Colloquium: TNOs are Cool - A Herschel survey of the trans-Neptunian region

by Esa Vilenius (MPE)

Wednesday 5 Feb 2014, 16:30 → 17:30 Europe/Berlin

seminar room, basement (Excellence Cluster Universe)

Trans-Neptunian objects (TNOs) are primitive remnants of the planetesimal disk from which the planets of our solar system formed. They are analogues to the parent bodies of dust in debris disks observed around other stars. Since 1992 about 1500 TNOs have been discovered but their basic physical properties have been challenging to measure. The richness of dynamical structure and varying physical properties set constraints to models of solar system formation and evolution. Herschel Space Observatory open time key program "TNOs are Cool" observed a sample of 130 TNOs at far-IR wavelengths around their thermal peaks. The results of radiometric modeling give albedo and size distributions as well as thermal properties. For binary systems we obtain an insight in their densities as a function of size. Thermal light curves of selected targets observed by Herschel are used together with the optical ones to solve the ambiguity between shape effects and albedo variegation. Possible correlations between physical properties The Universe Colloquium is followed by a social gathering with wine and cheese.