Stellar model chromospheres. XI. A survey of CaII lambda8542 line profiles in late-type stars of differing chromospheric activity

Journal Article · Thu Nov 01 04:00:00 EST 1979 · Astrophys. J., Suppl. Ser.; (United States)

DOI:https://doi.org/10.1086/190627· OSTI ID:5758118

Linsky, J L; Hunten, D M; Sowell, R; Glackin, D L; Kelch, W L

We have obtained profiles of the Ca II infrared triplet line lambda8542 in 49 stars of spectral type F9--K3. These data were obtained with a silicon diode vidicon detector system on the KPNO McMath telescope and have a spectral resolution of 0.14 A. We find no evidence for distinct emission features in the lambda8542 lines, even for the most active chromosphere stars, but instead find that the line cores are filled in for active chromospheric stars compared to quiet chromosphere stars of the same spectral type. We derive chromospheric radiative loss rates in the lambda8542 line and find good correlations with chromospheric radiative loss rates in the Ca II H and K lines and Mg II h and k lines and with the Wilson-Bappu K-line index. Thus the lambda8542 line is a good diagnostic of chromospheric activity. Computed lambda8542 line profiles for the seven stars for which model chromospheres are available are not in as good agreement with the data as we would like, and for the three modeled giants the addition of macroturbulence cannot account for discrepancies in the line cores. We account for variability in the ..cap alpha.. Aur line profile as due to orbital motions of ..cap alpha.. Aur B, and we point out circumstellar features, indicating both outflowing and inflowing material, in six supergiants.

• Research Organization: Joint Institute for Laboratory Astrophysics, National Bureau of Standards and University of Colorado
• OSTI ID: 5758118
• Journal Information: Astrophys. J., Suppl. Ser.; (United States), Journal Name: Astrophys. J., Suppl. Ser.; (United States) Vol. 41:3; ISSN APJSA
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATMOSPHERES
ATOMIC IONS
CALCIUM IONS
CAMERA TUBES
CHARGED PARTICLES
ENERGY LEVELS
FUNCTIONS
GIANT STARS
IMAGE TUBES
INFRARED SPECTRA
IONS
LINE WIDTHS
MATHEMATICAL MODELS
SPECTRA
SPECTRAL FUNCTIONS
STAR MODELS
STARS
STELLAR ATMOSPHERES
SUPERGIANT STARS
VIDICONS