High Dispersion SWP Spectra of Two DME Stars
Abstract
Low dispersion SWP spectra of AU Mic (dM2.5e) and AT Mic (dM4.5e+dM4.5e) indicate that these two M dwarfs likely have the brightest emission lines in the ultraviolet, and that it is feasible to obtain line profiles for lines of C II, Si IV, C IV, He II, and Si II in 8 hour SWP high dispersion spectra. We propose to extend our previous studies of dMe stars and high resolution studies of some 15 late-type dwarfs and luminous stars to include AU Mic and AT Mic. Our objectives are (1) to obtain widths of chromospheric and transition region lines for comparison with our previous observations of 5 GO-K2 dwarfs, and to determine the increase in turbulence with height in the atmosphere so as to constrain models of atmospheric heating, (2) to determine which lines are optically thick for comparison with computed model atmospheres, (3) to determine the flux and formation mechanism of the blended He II 1640 multiplet so as to derive the coronal soft X-ray radiation field, and (4) to compute models for the chromospheres and transition regions of these stars. In computing these models we will use fluxes and profiles (when available) for lines of Mg II, C II-IV, Si II-IV, and N V using computer codes that have already been written.
- Publication:
-
IUE Proposal
- Pub Date:
- 1982
- Bibcode:
- 1982iue..prop.1135L