Understanding the formation of planets remains one of astronomy''s most rewarding challenges, representing a significant component of the search for our own cosmic origins, and bearing on the possibility of life on other worlds. Although there is consensus that the evolution of gas and dust in disks around young stars is tied to planet formation, fundamental questions about this assumed coupling remain unanswered. Here, building on his previous work, Dr. Brittain will address these questions using high-resolution near-infrared spectroscopy to peer into the inner disks surrounding a class of young stars referred to as Herbig Ae/Be stars.
An important tool for tracing the evolution of circumstellar disks is the measurement of the spectral energy distribution of young stars. The differences in the spectral energy distributions have led to the proposal that they reflect an evolutionary sequence from optically thick disks to transitional disks (i.e. disks with optically thick outer disks and optically thin inner disks) to optically thin disks on a timescale commensurate with planet formation. The canonical interpretation of the distinctive transitional disk morphology is that it reflects dynamical sculpting by an embedded planet. However, there are other physical effects - namely grain growth and photo-evaporation - that can give rise to transitional disks with indistinguishable spectral energy distributions. In this project the distribution of warm gas in the disks of Herbig Ae/Be stars will be observed and used to differentiate these effects via their unique signatures. Such an understanding the true origin of transitional disk morphology has fundamental implications for understanding the formation of gas-giant exoplanets and future direct imaging campaigns attempting to detect them.
The undergraduate and graduate students involved with this project will have the opportunity to carry out research at one of the frontiers of modern observational astrophysics by exploiting the new partnership between the National Optical Astronomy Observatory and Clemson that provides unprecedented access to the required observing facilities - a situation conducive to launching the careers of many young scientists. Undergraduate students will be involved in this project through Clemson University''s novel Creative Inquiry initiative. This program matches teams of students with a faculty mentor for a multiyear project (typically five semesters) and provides modest funding to support their work. This work will also comprise a significant portion of a Clemson graduate student''s Ph.D. dissertation. The results of this research will be presented to the scientific community through peer-reviewed publications, colloquia, and talks at meetings as well as disseminated to the general public. This will be accomplished through continued popular presentations to the local community.
