Ultraviolet observations of cool stars. IV. Intensities of Lyman-$alpha$ and Mg II in epsilon Pegasi and epsilon Eridani, and line width-luminosity correlations

Journal Article · Mon Dec 15 04:00:00 EST 1975 · Astrophys. J., v. 202, no. 3, pp. 733-740

DOI:https://doi.org/10.1086/154026· OSTI ID:4056421

McClintock, W; Henry, R C; Moos, H W; Linsky, J L

The Princeton spectrometer on the Copernicus satellite has been used to confirm the existence of a line width--luminosity relation for the L$alpha$ and Mg II lambda2800 chromospheric emission lines in K-type stars, by observation of a K2 dwarf (epsilon Eri) and of a K2 supergiant (epsilon Peg). Combined with previously reported observations of lines in three K giants ($alpha$ Boo, $alpha$ Tau, and $beta$ Gem), the data are consistent with an identical dependence of line-width on absolute visual magnitude for the Ca II K, L$alpha$, and Mg II lambda2795 lines. Surface fluxes of L$alpha$, Mg II lambda2800, and O v lambda1218 (upper limit) for epsilon Eri, and of Mg II lambda2800 for epsilon Peg are also compared with values reported previously for the three giant stars. (AIP)

• Research Organization: Physics Department, Johns Hopkins University
• Sponsoring Organization: USDOE
• NSA Number: NSA-33-024024
• OSTI ID: 4056421
• Journal Information: Astrophys. J., v. 202, no. 3, pp. 733-740, Journal Name: Astrophys. J., v. 202, no. 3, pp. 733-740; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

*DWARF STARS-- ULTRAVIOLET SPECTRA
*SUPERGIANT STARS-- ULTRAVIOLET SPECTRA
640102* --Physics Research--Astrophysics & Cosmology--Stars
CALCIUM
CHROMOSPHERE
EMISSION SPECTRA
LINE WIDTHS
LUMINOSITY
LYMAN LINES
MAGNESIUM
N56200* --Physics (Astrophysics & Cosmology)--Stars