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arXiv · astro-ph/9801274

A CORAVEL radial-velocity monitoring of S stars: symbiotic activity vs. orbital separation

J. M. Carquillat·A. Jorissen·S. Udry·N. Ginestet
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Abstract

Orbital elements are presented for the Tc-poor S stars HR 363 (= HD 7351) and HD 191226. With an orbital period of 4592 d (=12.6 y), HR 363 has the longest period known among S stars, and yet it is a strong X-ray source. Its X-ray flux is similar to that of HD 35155, an S star with one of the shortest orbital periods (640 d). This surprising result is put in perspective with other diagnostics of binary interaction observed in binary S stars. They reveal that there is no correlation between the level of binary interaction and the orbital period. This situation may be accounted for if the wind mass-loss rate from the giant is the principal factor controlling the activity level in these (detached) systems, via a stream of matter funneled through the inner Lagragian point.

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J. M. Carquillat, A. Jorissen, S. Udry, N. Ginestet. 1998-01-28. A CORAVEL radial-velocity monitoring of S stars: symbiotic activity vs. orbital separation. https://doi.org/10.1051/aas%3A1998251

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