TNOs are Cool: Thermophysical modeling of a sample of 20 classical KBOs using Herschel/PACS

International audienceWe determine the sizes and albedos of 20 classical Kuiper belt objects. Our observations with the PACS instrument on-board Herschel Space Observatory cover the wavelength range where the thermal emission from trans-Neptunian objects has its maximum. We use a consistent method for data reduction and aperture photometry of this sample, and determine sizes and albedos using thermophysical models. We compare the results to previous ground- and spacebased estimates. Our new results confirm the recent findings that there are very diverse albedos among the classical KBOs, which has important implications to their global properties, such as size distribution and the total mass of the belt. An increased average albedo would mean a decreased total mass of these targets. Almost all of the 20 targets have higher albedos than assumed. There are variations between the different groups within our sample: the cold classicals together with the two inner hot classicals have higher albedos than the hot classicals. Our refined sizes and albedos make an important contribution to the estimates of the fundamental properties of these objects