Observational and Theoretical Constraints on the Detectability and Occurrence Rate of Massive Collisions in the Beta Pictoris System

Although it is thought that the grinding down of planetesimals sustain the dust we see in debris disks, the occurrence rate and detectability of such collisions is not well understood. Beta Pictoris is an archetypal debris disk system whose proximity, brightness, and planetary system offers a unique opportunity to study the dynamical evolution of young planetary systems. We present new, multi-epoch imaging of the Beta Pictoris debris disk in scattered light with HST/STIS. We present the highest precision, longest baseline surface brightness measurement variations from 1997 to 2025. Our measurement baseline, combined with Beta Pic b’s 20 year orbital period, allows us to test model predictions of planet-disk interactions in debris disks. On the other hand the surface brightness variation measurements of the high SNR, outer regions of the disk (50-200 au) allowed us to search for signs of recent collisional remnants and place constraints on the minimum mass collisional progenitor we are sensitive to with regular HST/STIS monitoring. We additionally present new theoretical work on the rate and probability of massive planetesimal collisions in debris disks. By varying disk parameters, we are able to provide a collision rate for a range progenitor sizes, which is then compared to observational evidence of collisions in debris disks like Fomalhaut and Beta Pic. Finally, using a combination of observational and theoretical constraints, we provide monitoring guidance on cadence and targets for HST and JWST.