Abstract

Only 20% of old field stars have detectable analogues to our Asteroid and Kuiper belts which are called debris discs. This leaves open the question of what disc, if any, is present around the remaining 80%. Young moving groups allow to probe this population, since discs are expected to have been brighter early on. We consider the population of F stars in the 23 Myr-old BPMG where we find that 9/12 targets possess discs and compare it to disc samples from ∼45 Myr and ∼150 Myr-old moving groups, and to discs found around field stars. We find that the disc luminosities in the populations considered drop by two orders of magnitude within the first 100 Myr. This is much faster than expected by collisional evolution! In this talk, we investigate different scenarios that could explain the fast evolution of the debris discs in the BPMG .