Project Title: Winds and Accretion in Young Stars

Project Advisor: Dr. Andrea Dupree

Background: The recent discovery of fast, hot winds from young stars evidenced through infrared and ultraviolet spectroscopy impacts many aspects of low mass star formation. A sufficiently robust stellar wind may lead to optical jets, could remove angular momentum from the star, contribute to the opacity needed for X-ray absorption, and influence the diminution of dust in accretion disks. It is important to characterize these winds, and determine the mass loss rates, wind speeds, and temperatures in the outer atmospheres and their relation to the mass accretion rate.

Scientific Questions: Where does mass loss occur? What are the influences of the surrounding disks? How much material is lost? When does the wind develop in young stars? How does the mass loss rate relate to the mass accretion rate? What is the geometry of the outflow?

Scientific Methodology: We have Magellan/MIKE echelle spectra, infrared spectra, and far ultraviolet spectra of a number of young stars. Additionally in early 2007, there is an international campaign to moniter the nearest accreting young star, TW Hya at both X-ray and optical wavlengths. We want to construct semi-empirical models of the chromospheres of these stars to obtain a quantitative determination of wind properties. Opportunities exist for analysis of optical, far UV, and X-ray spectra of young stars, and for sophisticated radiative transfer calculations of line profiles in moving media.