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EUV Spectroscopy of Bright Hyades Coronae: 71 Tauri and Theta 1 Tauri
| Content Provider | Semantic Scholar |
|---|---|
| Author | Stern, Robert A. |
| Copyright Year | 1992 |
| Abstract | We report results from the first extreme ultraviolet spectrum of the prototype eclipsing binary Algol (/3 Per), obtained with the spectrometers on the Extreme Ultraviolet Explorer (EUVE). The Algol spectrum in the 80-350/_ range is dominated by emission lines of Fe XVI-XXIV, and the He II 304 /_ line. The Fe emission is characteristic of high temperature plasma at temperatures up to at least log T -,7.3 K. We have successfully fit the observed quiescent spectrum using a continuous emission measure distribution with the bulk of the emitting material at log T > 6.5. We are able to adequately model both the coronal lines and continuum data with a cosmic abundance plasma, but only if Algol's quiescent corona is dominated by material at log T > 7.5, which is physically ruled out by prior X-ray observations of the quiescent Algol spectrum. Since the coronal [Fe/H] abundance is the principal determinant of the line-to-continuum ratio in the EUV, allowing the abundance to be a free parameter results in models with a range of best fit abundances _ 15-35% of solar photospheric [Fe/H]. Since Algol's photospheric [Fe/H] appears to be near-solar, the anomalous EUV line-to-continuum ratio could either be the result of element segregation in the coronal formation process, or other, less likely mechanisms that may enhance the continuum with respect to the lines. Subject headings: ultraviolet: stars, stars: coronae, binaries: eclipsing |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19950011976.pdf |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
