Herschel Space Observatory (HSO) is a mission of the European Space Agency (ESA) and of the National Aeronautics and Space Administration (NASA). “TNOs are Cool!” is a key-project of HSO dedicated to the observations of thermal emission from 130 Trans-Neptunian Objects and Centaurs in around 400h of observing time (Müller et al., (2009)).
For the analysis and interpretation of the thermal data from HSO, thermal models or thermophysical models are required. To derive diameters and albedos, all these models require input parameters such as absolute magnitudes and spin periods or constraints on them, all of which require ground based photometry. I participated in several ground-based observations used as complement for the HSO key program. I provided astrometry, short-term variability, and binary study for most of the HSO targets.