Ultraviolet observations of cool stars. IV. Intensities of Lyman-$alpha$ and Mg II in epsilon Pegasi and epsilon Eridani, and line width-luminosity correlations
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, Other Information: Orig. Receipt Date: 30-JUN-76
- Country of Publication:
- United States
- Language:
- English
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