The chromospheres of late-type stars. II. an atlasofchromospheric lines for selected early-K stars.
Abstract
High-resolution spectra of the chromospheric Na I D lines, Ca I 4227, Mg I 4571, 5167, and 5172, the Ca II H and K resonance and IR 8542.144 and 8662.170 lines, and H-alpha and H-beta, all observed simultaneously at the AAT, are presented. These data are presented as the observational basis for the self-consistent, semiempirical modeling of the outer photospheres and chromospheres of the target stars. Stellar activity is found in the low-chromosphere lines as core-filling and, in some stars, as line-broadening. Integrated fluxes are derived from the difference spectra, formed by subtracting quiet from active spectra, in the Ca II H and K resonance and IR 8542 and 8662 lines and in H-alpha, which are presented as chromospheric activity indicators. All the activity indices exhibit strong correlations, with the exception of the equivalent widths of H-alpha and H-beta, which are found to be relatively poor activity discriminators.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- May 1993
- DOI:
- 10.1093/mnras/262.1.1
- Bibcode:
- 1993MNRAS.262....1T
- Keywords:
-
- Chromosphere;
- K Stars;
- Late Stars;
- Line Spectra;
- Stellar Radiation;
- Stellar Spectra;
- D Lines;
- H Alpha Line;
- H Beta Line;
- Photosphere;
- Resonance Lines;
- Astrophysics