Orbital Dynamics

Overview

Many exoplanets are detected indirectly, based on precise measurements of the motion of the star which is influenced by the gravitational tug of any nearby planets. Therefore, accurately characterizing the star and planets’ orbits is an important part of planet discoveries.  In planetary systems with multiple planets, the relationships between their orbits often provides clues about how the system formed.  In some planetary systems, the interactions between closely-spaced planets cause their orbits to evolve over long timescales, sometimes reaching billions of years.  In a few cases, astronomers can already detect such changes in planets’ orbits, providing valuable information about the planets’ masses and orbits.

Areas of Specialty

• Characterizing Architectures of Multiple Planet Systems
  • High-Precision Doppler Spectroscopy (Wright, Wolszczan, Dawson, Ford)
  • Transit Timing Variations (Dawson, Ford)
  • Pulsar Timing (Wolszczan)
• Late-stages of Planet Formation (Dawson, Ford, Sigurdsson)
• Long-term Orbital Evolution of Planetary Systems (Dawson, Ford, Sigurdsson)

Faculty Contacts

• Rebekah Dawson studies the dynamical histories of planetary systems, including the origins of hot and warm Jupiters, the early evolution of compact super-Earth systems that establishes their orbital and compositional properties, the migration of planets in our young Solar System, and chaotic system of inner Uranian moons.
• Eric Ford  studies how gravitational interactions between planets during the late stages of planet formation can sculpt the architecture of planetary systems that astronomers observe today.  Ford also helps perform the statistical and dynamics modeling necessary to accurately interpret complex observations of rapidly interacting planetary systems, including Doppler and transit timing observations.
• Steinn Sigurdsson  investigates the accretion of rocky planets and the transport of volatiles across the solar system.
• Darrin Williams studies the orbital stability and dynamical characteristics of extrasolar planets and moons in support of telescopic programs attempting to observe them.
• Alex Wolszczan  discovered the first exoplanets by precisely timing the PSR 1257 +12 pulsar.  It hosts multiple low-mass planets, including two that are strongly interacting, enabling precise measurements of the planet’s masses and orbits.  Prof. Wolszczan also leads a Doppler planet search using the Hobby-Eberly Telescope (HET) to observe evolved stars, many of which harbor multiple giant planets.
• Jason Wright  conducts high-precission Doppler measurements of stars with multiple planet systems, so as to characterize the planet masses and orbits.  Prof. Wright’s group observes with the 10m Keck Observatory in collaboration with the California Planet Survey, and is planning upcoming Doppler planet surveys using the upgraded Hobby-Eberly Telescope (HET) and MINERVA observatories.