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arXiv · 1012.1720

A search for star-planet interactions in chromospheric lines

L. F. Lenz·A. Reiners·M. Kürster
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Abstract

Massive planets in very close orbits around their central stars can induce so-called star-planet interactions (SPI), which may be of magnetic or gravitational nature. In both cases, SPI can potentially cause recurring chromospheric emission on the host star visible in Ca II H & K and/or H$\alpha$. The emission would be bound to the planetary orbit, not to the rotation period of the star. We searched for SPI in a sample of 7 stars with massive close-in planets using high-resolution spectroscopic data taken at HRS (HET) and FEROS (La Silla). We find no periodically recurring emission in the planet-hosting stars. In the case of HD 41004 AB, a binary system consisting of a K dwarf and an M dwarf, where the M dwarf is orbited by a brown dwarf companion, we find signs of cyclic variation in the Ca II K and H$\alpha$ emission lines that could be associated to interactions between the M dwarf and its companion. We present our first results of this interesting system that may become an important system for the understanding of SPI.

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L. F. Lenz, A. Reiners, M. Kürster. 2010-12-08. A search for star-planet interactions in chromospheric lines. https://arxiv.org/abs/1012.1720

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