Small rocks, big data: towards centaurs, Neptune trojans, and comets in the Legacy Survey of Space and Time

Centaurs, Neptune Trojans, and Jupiter-family comets record primordial conditions as well as ongoing dynamical and physical processing, but progress has been limited by small sample sizes and scarce colour or light curve data. The Vera C. Rubin Observatory’s Legacy Survey of Space and Time (LSST) will change this by delivering deep, high-cadence, multi-filter photometry and increase known populations by orders of magnitude.<br><br>I used the survey simulator tool Sorcha to provide the first predictions of the LSST discovery yields for Centaurs and Neptune Trojans.

For Centaurs, the known population should grow by nearly an order of magnitude, with more than a thousand new objects expected over ten years and roughly half detected within the first two. For Neptune Trojans, current detections are heavily biased toward the L4 cloud, but the LSST should uncover several hundred objects in both L4 and L5, sampling both regions for the first time. In both populations, hundreds of observations per object across multiple filters will support tests of colour distributions, measurements of activity fractions, and links between surface properties, orbits, and dynamical histories.<br><br>Finally, I also carried out case studies of comet 103P/Hartley 2 and the Centaur (2060) Chiron to demonstrate how survey photometry can diagnose activity.