# Magnetic cycles of the planet-hosting star τ Bootis – II. A second magnetic polarity reversal

@article{Fares2009MagneticCO,
title={Magnetic cycles of the planet-hosting star $\tau$ Bootis – II. A second magnetic polarity reversal},
author={R Fares and Jean-François Donati and Claire Moutou and David Bohlender and Claude Catal{\a} and Magali Deleuil and Evgenya L. Shkolnik and Andrew Collier Cameron and M. M. Jardine and Gordon Arthur Hunter Walker},
journal={Monthly Notices of the Royal Astronomical Society},
year={2009},
volume={398},
pages={1383-1391}
}`
• R. Fares, +7 authors G. Walker
• Published 2009
• Physics
• Monthly Notices of the Royal Astronomical Society
In this paper, we present new spectropolarimetric observations of the planet- hosting starBootis, using ESPaDOnS and Narval spectropolarimeters at Canada- France-Hawaii Telescope (CFHT) and Telescope Bernard Lyot (TBL), respectively. We detected the magnetic field of the star at three epochs in 2008. It is a weak magnetic field of only a few Gauss, oscillating between a predominant toroidal com- ponent in January and a dominant poloidal component in June and July. A magnetic polarity reversal… Expand
137 Citations

#### Figures and Tables from this paper

A small survey of the magnetic fields of planet-host stars
Using spectropolarimetry, we investigate the large-scale magnetic topologies of stars hosting close-in exoplanets. A small survey of 10 stars has been done with the twin instruments Telescope BernardExpand
Magnetic field, differential rotation and activity of the hot-Jupiter-hosting star HD 179949
HD 179949 is an F8V star, orbited by a giant planet at similar to 8 R? every 3.092 514 d. The system was reported to undergo episodes of stellar activity enhancement modulated by the orbital period,Expand
The magnetic properties of the star Kepler-78
• Physics
• 2016
Kepler-78 is host to a transiting 8.5-h orbit super-Earth. In this paper, the rotation and magnetic properties of the planet host star are studied. We first revisit the Kepler photometric data for aExpand
Direct observation of magnetic cycles in Sun-like stars
A sample of 19 solar-type stars, probing masses between 0.6 and 1.4 solar mass and rotation periods between 3.4 and 43 days, was regularly observed using the NARVAL spectropolarimeter at TelescopeExpand
∊ Eridani: an active K dwarf and a planet hosting star?. The variability of its large-scale magnetic field topology
• Physics
• 2014
The young K-dwarf Eridani is an example of a young active planet hosting star that has shown over long-term monitoring of its chromospheric emission to exhibit cyclic magnetic activity. In thisExpand
A solar-like magnetic cycle on the mature K-dwarf 61 Cygni A (HD 201091)
The long-term monitoring of magnetic cycles in cool stars is a key diagnostic in understanding how dynamo generation and amplification of magnetic fields occur in stars similar in structure to theExpand
Searching for star–planet interactions within the magnetosphere of HD 189733
HD 189733 is a K2 dwarf, orbited by a giant planet at 8.8 stellar radii. In order to study magnetospheric interactions between the star and the planet, we explore the large-scale magnetic field andExpand
The stellar wind cycles and planetary radio emission of the τ Boo system
t Boo is an intriguing planet-host star that is believed to undergo magnetic cycles similar to the Sun, but with a duration that is about one order of magnitude smaller than that of the solar cycle.Expand
MOVES – I. The evolving magnetic field of the planet-hosting star HD189733
HD189733 is an active K dwarf that is, with its transiting hot Jupiter, among the most studied exoplanetary systems. In this first paper of the Multiwavelength Observations of an eVaporatingExpand
The evolving magnetic topology of τ Boötis
We present six epochs of spectropolarimetric observations of the hot-Jupiter-hosting star tau Bootis that extend the exceptional previous multiyear data set of its large-scale magnetic field. OurExpand

#### References

SHOWING 1-10 OF 30 REFERENCES
Magnetic cycles of the planet-hosting star τ Bootis
We have obtained new spectropolarimetric observations of the planet-hosting star τ Bootis, using the ESPaDOnS and NARVAL spectropolarimeters at the Canada-France-Hawaii Telescope (CFHT) and TelescopeExpand
The magnetic field of the planet‐hosting star τ Bootis★
• Physics
• 2007
We have obtained high-resolution spectropolarimetric data for the planet-hosting star τ Bootis, using the ESPaDOnS spectropolarimeter at the Canada‐France‐Hawaii Telescope (CFHT). A weak but clearExpand
The surprising magnetic topology of τ Sco: fossil remnant or dynamo output?
We report the discovery of a medium-strength (~0.5 kG) magnetic field on the young, massive star ? Sco (B0.2V), which becomes the third-hottest magnetic star known. Circularly polarized ZeemanExpand
Spectropolarimetric observations of the transiting planetary system of the K dwarf HD 189733
With a Jupiter-mass planet orbiting at a distance of only 0.031 AU, the active K2 dwarf HD 189733 is a potential candidate in which to study the magnetospheric interactions of a cool star with itsExpand
Hot Jupiters and stellar magnetic activity
Context. Recent observations suggest that stellar magnetic activity may be influenced by the presence of a close-by giant planet. Specifically, chromospheric hot spots rotating in phase with theExpand
The stable magnetic field of the fully convective star V374 Peg
We report in this paper phase-resolved spectropolarimetric observations of the rapidly rotating fully convective M4 dwarf V374 Peg, on which a strong, mainly axisymmetric, large-scale poloidalExpand
Extrasolar planets, stellar winds and chromospheric hotspots
• Physics
• 2006
Recent observations have shown what is believed to be planet-induced chromospheric activity on stars with hot Jupiters. We present a model of the magnetic interaction between a planet and a star withExpand
Simulated X-ray cycles in rapidly rotating solar-like stars
• Physics
• 2006
It is generally accepted that the presence of a hot magnetic corona provides the source of X-ray emission in cool stars. With this connection one could expect to see the variation of magnetic flux inExpand
Hot Jupiters and hot spots: The Short- and long-term chromospheric activity on stars with giant planets
• Physics
• 2005
We monitored the chromospheric activity in the Ca II H and K lines of 13 solar-type stars (including the Sun): 8 of them over 3 years at the Canada-France-Hawaii Telescope (CFHT) and 5 in a singleExpand
Evidence for Planet-induced Chromospheric Activity on HD 179949
• Physics
• 2003
We have detected the synchronous enhancement of Ca II H and K emission with the short-period planetary orbit in HD 179949. High-resolution spectra taken on three observing runs extending over moreExpand