Wood, Brian, E.

Contact Email: woodb@casa.colorado.edu
Institute: JILA, University of Colorado
First Coauthor: Hans-Reinhard Mueller
Institute: Bartol Research Institute
Second Coauthor: Gary Zank
Institute: Bartol Research Institute
Subject Area: Stellar Atmospheres, Circumstellar Material
Waveband: Ultraviolet
Technique: Spectroscopy
Presentation: Oral Contribution: Thursday
Title: Mass-Loss Rates for Solar-like Stars Measured from Ly$\alpha$ Absorption
Abstract: We present a number of mass-loss rate estimates for solar-like stars with coronal winds ($\alpha$ Cen AB, Proxima Cen, $\epsilon$ Eri, $\epsilon$ Ind, $\lambda$ And, 40 Eri A, 61 Cyg AB, 36 Oph AB), measured using a Ly$\alpha$ absorption technique. The collision between the solar wind and the interstellar wind seen by the Sun in its rest frame creates a heliospheric structure around the Sun that has been the subject of theoretical study for many decades. Similar structures, ``astrospheres'', should exist around other solar-like stars. The deceleration of the interstellar wind at a stellar bow shock heats the plasma component of the interstellar material, and the neutrals are then heated as well by charge exchange processes. Heated neutral hydrogen in the outer astrosphere (and in our own heliosphere) produces a broad Ly$\alpha$ absorption profile that is at least partially separable from the interstellar H I absorption in high resolution Hubble Space Telescope spectra. With guidance from hydrodynamic models of astrospheres, we use detected astrospheric Ly$\alpha$absorption to estimate the stellar mass-loss rates.