Department of Astronomy Center for Radiophysics & Space Research

Kassandra Anderson

Current graduate student in exoplanetary systems


Kassandra is a second-year graduate student working with Professor Dong Lai on the dynamics of exoplanetary systems, with a focus on the orbital evolution and migration of hot Jupiters.  Currently, she studies the dynamics of "high eccentricity migration," in which planets can be perturbed by distant companion stars, and be periodically excited into very eccentric orbits.  Due to dissipative tidal forces between the planet and host star, the planetary orbit shrinks, causing the planet to gradually migrate inward and settle into a tight orbit around its host star. 

Motivated by observed spin-orbit misalignments in hot Jupiter systems, Kassandra's work focuses on the spin-orbit dynamics between the migrating planet and the host star.  When the migrating planet is at high-eccentricity, the host star experiences torques from the planet, causing the stellar spin axis to evolve in a complex manner.  In collaboration with Professor Lai and Physics graduate student Natalia Storch, she is seeking observational consequences of these spin dynamics.  By simulating the evolution of the stellar spin, she is comparing the theoretical results with the distribution of observed spin-orbit misalignment angles.  Such calculations are useful for distinguishing between various possible migration channels for hot Jupiters. 

Kassandra's research interests include the general area of stellar and planetary astrophysics, circumstellar disks, and dynamics.  Using a combination of numerical simulations and semi-analytic techniques, her long-term goal is to better understand the diverse architectures of observed exoplanetary systems.  In addition to research, she is also taking classes, and participating in Cornell's Ask an Astronomer outreach program.  Outside of astronomy, she has a variety of activities and hobbies, including sewing and knitting, dance, and hiking around Ithaca.

Kassandra chose to come to Cornell because of the research opportunities in the department and the strong sense of community among its members.  "The environment here is very friendly, yet also stimulating.  As graduate students, we have opportunities to interact and collaborate not only with the local faculty and research scientists, but also with visiting scientists, and weekly colloquium and seminar speakers.  These interactions are really helpful."

Kassandra proposed for and was awarded an NSF Graduate Research Fellowship to support her in her PhD.