The number of exoplanets--planets around stars other than the Sun--has grown into the thousands in the past decade. The vast majority of the known exoplanets have been found closer to their star than the Earth is to our Sun. At the distances of stars, this is too small a spacing to be easily resolved. The investigators plan to use a new technique (infrared interferometry) and a new instrument (MYSTIC), to study how Earth-like planets form and develop. Preliminary studies of planets suggest a gap in planet size distribution between 1.5 and 2 times the radius of the Earth, and the investigators will seek to confirm or disprove that result. Graduate students and undergraduate students will be involved in the research. The investigators will also team with the Ann Arbor Hands-On Museum to 1) create mobile versions of museum displays that will travel the state of Michigan and 2) create a hands-on exhibit and booth to travel to NASCAR events in Michigan in order to provide science outreach to an audience that might not currently be seeking STEM experiences.
The region inside 1 au around young stars is physically small on an astronomical scale. However, the physics in this region has an out-sized impact: this is where mass accretion onto the star is regulated, the initial conditions for terrestrial planet formation are set, and the migration of giant planets moving through the young gas-rich disk are controlled, Exoplanet demographics of the inner au now reveal a gap in the planet size distribution and also suggest the budget of solids available may not be enough to explain the known Kepler planets, at least using current disk models. To directly address the intimate connections between planet-formation theory and exoplanet demographics, spatially-resolved imaging of the inner au of young stars is needed. This can only be reached through infrared interferometry. Using the Georgia State University CHARA Array (the longest-baseline optical/infrared interferometer in the world) the investigators will image young stars with milliarcsecond angular resolution at wavelengths from 1.1-2.5 microns for the first time.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
