| Autor: |
A. N. Parmar, J. L. Culhane, N. E. White, R. A. Shafer, K. Horne |
| Rok vydání: |
1990 |
| Předmět: |
|
| Zdroj: |
International Astronomical Union Colloquium. 115:175-186 |
| ISSN: |
0252-9211 |
| Popis: |
The eclipsing RS CVn system AR Lac (G2IV+K0IV) has been observed continuously for one 2 day binary cycle with the EXOSAT observatory. Below 1 keV a factor of two intensity modulation is seen with a flat bottomed minimum around the time of primary eclipse and a shallow dip preceeding primary eclipse. Above 1 keV, where only emission with temperatures > 107 K would be detected, no orbital modulation or eclipse is seen. This suggests that the > 20 million degree emission comes from a large region, comparable in size to the binary seperation. The modulation in the < 1 keV lightcurve has been modelled by x2 fitting to X-ray bright spots and by using maximum entropy deconvolution. The lower temperature emission is found to orginate in compact regions with a pressure and temperature similar to that of the flaring sun. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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