The relation between stellar magnetic field geometry and chromospheric activity cycles II: The rapid 120 day magnetic cycle of Tau Bootis

Abstract

One of the aims of the BCool programme is to search for cycles in other stars and to understand how similar they are to the Sun. In this paper we aim to monitor the evolution of $\tau$ Boo's large-scale magnetic field using high-cadence observations covering its chromospheric activity maximum. For the first time, we detect a polarity switch that is in phase with $\tau$ Boo's 120 day chromospheric activity maximum and its inferred X-ray activity cycle maximum. This means that $\tau$ Boo has a very fast magnetic cycle of only 240 days. At activity maximum $\tau$ Boo's large-scale field geometry is very similar to the Sun at activity maximum: it is complex and there is a weak dipolar component. In contrast, we also see the emergence of a strong toroidal component which has not been observed on the Sun, and a potentially overlapping butterfly pattern where the next cycle begins before the previous one has finished.

6 pages, accepted by MNRAS

References in corpus (14)

• The surprising magnetic topology of tauSco: fossil remnant or dynamo output?
• The signature of orbital motion from the dayside of the planet tau Bootis b
• Magnetic cycles of the planet-hosting star tauBootis
• Magnetic cycles of the planet-hosting star Tau Bootis: II. a second magnetic polarity reversal
• Solar Magnetic Field Reversals and the Role of Dynamo Families
• The magnetic field of the planet-hosting star $\tau$ Bootis
• A small survey of the magnetic fields of planet-host stars
• The connection between stellar activity cycles and magnetic field topology
• A solar-like magnetic cycle on the mature K-dwarf 61 Cyg A (HD 201091)
• The GAPS Programme with HARPS-N at TNG. VII. Putting exoplanets in the stellar context: magnetic activity and asteroseismology of $\tau$ Bootis A
• The Evolving Magnetic Topology of $\tau$ Boötis
• The magnetic field vector of the Sun-as-a-star
• The relation between stellar magnetic field geometry and chromospheric activity cycles I: The highly variable field of Epsilon Eridani at activity minimum
• A magnetic cycle of tau Bootis? The coronal and chromospheric view

Cited by in corpus (32)

• Magnetic field strengths of hot Jupiters from signals of star-planet interactions
• The search for radio emission from the exoplanetary systems 55 Cancri, $\upsilon$ Andromedae, and $\tau$ Boötis using LOFAR beam-formed observations
• Estimating magnetic filling factors from Zeeman-Doppler magnetograms
• Powering Stellar Magnetism: Energy Transfers in Cyclic Dynamos of Sun-like Stars
• Estimating activity cycles with probabilistic methods II. The Mount Wilson Ca H&K data
• Direct evidence of a full dipole flip during the magnetic cycle of a sun-like star
• Observing the simulations: Applying ZDI to 3D non-potential magnetic field simulations
• Monitoring the large-scale magnetic field of AD~Leo with SPIRou, ESPaDOnS and Narval. Toward a magnetic polarity reversal?
• Linking chromospheric activity and magnetic field properties for late-type dwarf stars
• The Solar Wind in Time II: 3D stellar wind structure and radio emission
• Hunting for exoplanets via magnetic star-planet interactions: geometrical considerations for radio emission
• Zeeman-Doppler imaging of five young solar-type stars
• Identifying solar-like magnetic cycles with Zeeman-Doppler-Imaging (ZDI)
• Influence of the Sun-like magnetic cycle on exoplanetary atmospheric escape
• Lambda And: A post-main sequence wind from a solar-mass star
• The space weather around the exoplanet GJ 436b
• Magnetic field and chromospheric activity evolution of HD75332: a rapid magnetic cycle in an F star without a hot Jupiter
• Topological changes in the magnetic field of LQ Hya during an activity minimum
• The CARMENES search for exoplanets around M dwarfs. Variability on long timescales as seen in chromospheric indicators
• The Effect of Magnetic Variability on Stellar Angular Momentum Loss II: The Sun, 61 Cygni A, $\epsilon$ Eridani, $\xi$ Bootis A and $\tau$ Bootis A
• Time evolution of magnetic activity cycles in young suns: The curious case of kappa Ceti
• Follow-up LOFAR observations of the $\tau$ Boötis exoplanetary system
• Constraining the orbit of the planet-hosting binary $\tau$ Boötis: Clues about planetary formation and migration
• Polarization of hot Jupiter systems: a likely detection of stellar activity and a possible detection of planetary polarization
• A BCool survey of stellar magnetic cycles
• Space environment and magnetospheric Poynting fluxes of the exoplanet $\tau$ Boötis b
• Sounding stellar cycles with Kepler - III. Comparative analysis of chromospheric, photometric and asteroseismic variability
• Slingshot prominences: a hidden mass loss mechanism
• Star-Planet Interactions: A Computational View
• Multicomponent Activity Cycles using Hilbert-Huang Analysis
• Magnetic field morphologies in convective zones influenced by a turbulent surface layer
• Far beyond the Sun: III. The magnetic cycle of $\mathbf{\iota }$ Horologii