| Description |
Planet formation leads to two detectable outcomes - planets and debris disks. No correlation between these outcomes has been found for main sequence FGK stars. However, planet formation outcome depends on spectral type. Furthermore, the higher incidence of both planets and debris for A stars makes correlations easier to detect. We propose to test for a debris-planet correlation around A stars, by observing 36 subgiants (retired A stars) with PACS to search for debris disk emission. All of these stars have been searched for planets, and 18 have detections.
Our population models, calibrated to main sequence disk evolution statistics, predict that we should detect disks toward 23% of our sample. Comparison of debris incidences in the planet and control samples will quantify any debris-planet correlation, which would provide valuable constraints for planet formation models. Even without such a correlation, we expect to find 4 debris-planet systems, adding to the 10 currently known, which would provide a significant advance in our understanding of the dynamics of planet-disk interactions, and so of how these systems could have formed. Also, since the post-main sequence debris disk population is currently poorly known, any disk discovery (or lack of it) will provide important new constraints on the evolution of debris in this phase. |
