UC Santa Cruz has been a world leader in the astrophysics of stellar and planetary formation and evolution, exoplanet detection and characterization, galactic populations and stellar nucleosynthesis. We have a history of strength in both observational and theoretical astrophysics.

Our Astrobiology Initiative Director, Natalie Batalha, led the science team for NASA’s Kepler Mission, a space telescope which detected thousands of exoplanets and led to humanity’s first estimates for the frequency of Earth-sized planets around other stars. She’s had a front row seat to exoplanet discovery since the very first discovery was announced in Florence in 1995. She led Kepler’s first planet discovery catalogs and worked to ensure that the mission would enable studies of exoplanet demographics for decades to come.

We now know that planets are not only common around other stars but also diverse. The knowledge catalyzed a push to better understand the atmospheres and interiors of exoplanets as well as the architectures of planetary systems. Ruth Murray-Clay is a world leader in the physics of atmosphere loss driven by stellar heating. Jonathan Fortney has applied these mass-loss models to the planetary population, to predict how the loss of thick atmospheres can lead to the observed demographic of exoplanets found to date. Their theoretical models also connect the composition of planetary systems observed today to the host stars they orbit and make predictions that tie protoplanetary disks to planet formation and evolution.

Theoretical work in galactic nucleosynthesis is led by Enrico Ramirez-Ruiz. He works with observational astronomers like Raja GuhaThakurta and Sandra Faber to understand the distribution of elements that play a role in planetary habitability. This includes predictions of how the composition of planet-forming disks around young stars dictates the composition of forming planets. We strive to understand the connection between observable planetary properties and the elements observed in their parent stars.

Andy Skemer and Natalie Batalha are leading the two exoplanet programs in the Early Release Science program for NASA’s James Webb Space Telescope. Through direct imaging and transmissin spectroscopy, these two programs promise to yield some of the first studies of exoplanet atmospheres with Webb. Skemer has pioneered observational techniques to obtain infrared spectra of cool atmospheres, while Batalha is using the Keck telescope to characterize the planets identified by NASA’s TESS Mission that will make the best targets for atmospheric studies with Webb.

Understanding exoplanetary atmospheres requires diverse expertise of the physics of atmospheric radiation, convection, cloud formation, and chemistry. Jonathan Fortney and colleagues in Earth and Planetary Sciences study all aspects of this physics as applied to planets in the solar system and beyond. Scattering by grains in the atmospheres of cloudy, self-luminous exoplanets induces the polarization of thermally emitted radiation in the near-infrared. Rebecca Jensen-Clem is working to measure these features for the first time using the Gemini Planet Imager.

UC Santa Cruz aims to foster innovative collaborations with astronomers that visit our campus. Each summer, the Other Worlds Laboratory exoplanet summer program brings nearly 50 students, researchers, and faculty to Santa Cruz to break new ground in observations and theory, in planet formation, evolution, and atmospheric characterization. Our research innovation in the astrophysics of planets, coupled with this collaborative atmosphere, makes UC Santa Cruz a worldwide hub in exoplanetary science.

Read about our research in Instrumentation.