Yale Astronomy & Astrophysics Colloquium - Christopher Spalding

Event time: 
Thursday, March 5, 2020 - 2:30pm
Christopher Spalding
Speaker Institution: 
Yale University
Talk Title: 
The dynamical role of the Solar wind in the formation and evolution of the terrestrial planets
Event description: 

Abstract:  The recent influx of extrasolar planetary detections has provided a key window into the primordial environment sculpting planetary systems, including our own Solar system. In particular, young stars rotate substantially faster than the Sun, possess strong magnetic fields and consequently host powerful stellar winds. Additionally, extrasolar planets usually reside on orbits much closer-in than Mercury, implying that our Solar system was somehow “hollowed-out” during its history, leading to a mass-deficit interior to Mercury’s orbit. In this talk, I will demonstrate the underappreciated role played by the winds of host stars, including the Sun, in sculpting the final architectures of planetary systems. Specifically, young stellar winds, emanated from fast-rotating stars, impose an orbital drag upon planetary building blocks, causing migration of their primordial locations. I show how this affect can help explain Mercury’s anomalously large iron core. Finally, I describe the importance of the central star’s early quadrupolar gravitational potential in tilting and destabilizing extrasolar planetary systems, a mechanism inactive in the Solar system owing to our relatively large orbits.

Watson Center A-51 See map
60 Sachem Street
New Haven, CT 06511
Open to: 
General Public