Lyman Alpha Emission from Cool Dwarf Stars
Abstract
In late-type dwarf stars Lyman-alpha is an extremely bright emission line comparable in strength to the sum of all transition region lines. We propose to investigate the energy balance in the outer atmospheres of late-type dwarf stars by first determining whether the Ly-alpha emission is correlated best with emission features from the chromosphere, transition region, or corona (X-rays). This empirical result will then permit us to attempt to answer three theoretical questions: (1) Is the Lyman-alpha region heated from below (chromosphere) or above (corona)?, (2) Which mechanism determines the location of the transition region in late-type stars?, and (3) Are major revisions necessary for all existing theoretical models of magnetically closed and open coronal regions? We will use data from the archives and request observing time primarily for very short SWP-LO exposures. We discuss how to minimize problems due to noncontemporaneous observations, geocoronal emission, and interstellar absorption.
- Publication:
-
IUE Proposal
- Pub Date:
- July 1984
- Bibcode:
- 1984iue..prop.1842L