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arXiv · 0812.4859

Long-term photometric monitoring of the hybrid subdwarf B pulsator HS0702+6043

R. Lutz·S. Schuh·R. Silvotti·R. Kruspe·S. Dreizler
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Abstract

Pulsating subdwarf B stars oscillate in short-period $p$-modes or long-period $g$-modes. HS 0702 + 6043 is one of currently three objects known to show characteristics of both types and hence is classified as hybrid pulsator. We briefly present our analysis of the $g$-mode domain of this star, but focus on first results from long-term photometric monitoring in particular of the $p$-mode oscillations. We present a high-resolution frequency spectrum, and report on our efforts to construct a multi-season O--C diagram. Additionally to the standard (although nontrivial) exercise in asteroseismology to probe the instantaneous inner structure of a star, measured changes in the pulsation frequencies as derived from an {O--C} diagram can be compared to theoretical evolutionary timescales. Within the {EXOTIME} program, we also use this same data to search for planetary companions around extreme horizontal branch objects.

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R. Lutz, S. Schuh, R. Silvotti, R. Kruspe, S. Dreizler. 2008-12-28. Long-term photometric monitoring of the hybrid subdwarf B pulsator HS0702+6043. https://arxiv.org/abs/0812.4859

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