A BCool survey of stellar magnetic cycles

Abstract

The magnetic cycle on the Sun consists of two consecutive 11-yr sunspot cycles and exhibits a polarity reversal around sunspot maximum. Although solar dynamo theories have progressively become more sophisticated, the details as to how the dynamo sustains magnetic fields are still subject of research. Observing the magnetic fields of Sun-like stars are useful to contextualise the solar dynamo. The BCool survey studies the evolution of surface magnetic fields to understand how dynamo-generated processes are influenced by key ingredients, like mass and rotation. Here, we focus on six Sun-like stars with mass between 1.02 and 1.06 MSun and with 3.5-21 d rotation period. We analysed high-resolution spectropolarimetric data collected with ESPaDOnS, Narval and Neo-Narval. We measured the longitudinal magnetic field from least-squares deconvolution line profiles and inspected its long-term behaviour with a Lomb-Scargle periodogram and a Gaussian process. We applied Zeeman-Doppler imaging to reconstruct the large-scale magnetic field geometry at the stellar surface for different epochs. Two stars, namely HD 9986 and HD 56124 (Prot ~ 20 d) exhibit repeating polarity reversals of the radial or toroidal field component on time scales of 5 to 6 yr. HD 73350 (Prot = 12 d) has one polarity reversal of the toroidal component and HD 76151 (Prot=17 d) may have short-term evolution (2.5 yr) modulated by the long-term (16 yr) chromospheric cycle. HD 166435 and HD 175726 (Prot =3-5 d), manifest complex magnetic fields without cyclic evolution. Our findings indicate the potential dependence of the magnetic cycles nature with stellar rotation period. For the two stars with likely cycles, the polarity reversal time scale seems to decrease with decreasing rotation period or Rossby number. These results represent important observational constraints for dynamo models of solar-like stars.

38 pages, 23 figures (ten in main text and 13 in appendices), nine tables (three in the main text and six in the appendices). Accepted for publication in Astronomy & Astrophysics

References in corpus (125)

• Astropy: A Community Python Package for Astronomy
• The NumPy array: a structure for efficient numerical computation
• The Transiting Exoplanet Survey Satellite
• Binary companions of evolved stars in APOGEE DR14: Search method and catalog of ~5,000 companions
• The SIMBAD astronomical database
• The generalised Lomb-Scargle periodogram. A new formalism for the floating-mean and Keplerian periodograms
• The PLATO 2.0 Mission
• Understanding the Lomb-Scargle Periodogram
• The Solar Cycle
• No planet for HD 166435
• Chromospheric CaII Emission in Nearby F, G, K, and M stars
• Planets and Stellar Activity: Hide and Seek in the CoRoT-7 system
• Chromospheric Activity and Jitter Measurements for 2630 Stars on the California Planet Search
• X-ray astronomy of stellar coronae (Review)
• Least squares deconvolution of the stellar intensity and polarization spectra
• The stellar rotation--activity relationship in fully convective M dwarfs
• Toroidal versus poloidal magnetic fields in Sun-like stars: a rotation threshold
• CoRoT reveals a magnetic activity cycle in a Sun-like star
• The Dependence of Differential Rotation on Temperature and Rotation
• Chromospheric activity catalogue of 4454 cool stars. Questioning the active branch of stellar activity cycles
• Inferring probabilistic stellar rotation periods using Gaussian processes
• Magnetic Cycles and Rotation Periods of Late Type Stars from photometric time series
• From solar-like to anti-solar differential rotation in cool stars
• A Bcool magnetic snapshot survey of solar-type stars
• Magnetic cycles of the planet-hosting star tauBootis
• The evolution of surface magnetic fields in young solar-type stars I: the first 250 Myr
• Effects of M dwarf magnetic fields on potentially habitable planets
• Magnetic cycles of the planet-hosting star Tau Bootis: II. a second magnetic polarity reversal
• Multiple and changing cycles of active stars II. Results
• Magnetism, rotation, and nonthermal emission in cool stars -- Average magnetic field measurements in 292 M dwarfs
• Chromospheric activity as age indicator
• PolarBase: a data base of high resolution spectropolarimetric stellar observations
• M-dwarf stellar winds: the effects of realistic magnetic geometry on rotational evolution and planets
• A Kepler Study of Starspot Lifetimes with Respect to Light Curve Amplitude and Spectral Type
• Cyclic magnetic activity due to turbulent convection in spherical wedge geometry
• On differential rotation and overshooting in solar-like stars
• Global Seismology of the Sun
• Solar Magnetic Field Reversals and the Role of Dynamo Families
• Rapidly Rotating Suns and Active Nests of Convection
• The evolution of surface magnetic fields in young solar-type stars II: The early main sequence (250-650 Myr)
• The Mount Wilson Observatory S-index of the Sun
• A seismic signature of a second dynamo?
• Stellar chromospheric activity of 1,674 FGK stars from the AMBRE-HARPS sample I. A catalogue of homogeneous chromospheric activity
• Temporal fluctuations in the differential rotation of cool active stars
• Grand Minima and Equatorward Propagation in a Cycling Stellar Convective Dynamo
• A History of Solar Activity over Millennia
• Modeling the RV jitter of early M dwarfs using tomographic imaging
• A small survey of the magnetic fields of planet-host stars
• Magnetic Activity Cycles in the Exoplanet Host Star epsilon Eridani
• Reconciling solar and stellar magnetic cycles with nonlinear dynamo simulations
• Multiple dynamo modes as a mechanism for long-term solar activity variations
• Magnetic cycles at different ages of stars
• Differential rotation in K, G, F and A stars
• Investigating the young AU~Mic system with SPIRou: large-scale stellar magnetic field and close-in planet mass
• Estimating magnetic filling factors from Zeeman-Doppler magnetograms
• A solar-like magnetic cycle on the mature K-dwarf 61 Cyg A (HD 201091)
• Magnetic field and wind of Kappa Ceti: towards the planetary habitability of the young Sun when life arose on Earth
• Long-term magnetic field monitoring of the Sun-like star ξBootis A
• Exploring the $P_{cyc}$ vs $P_{rot}$ relation with flux transport dynamo models of solar-like stars
• Hidden magnetic fields of young suns
• Activity trends in young solar-type stars
• Planet-induced radio emission from the coronae of M dwarfs: the case of Prox Cen and AU Mic
• Evolution of coexisting long and short period stellar activity cycles
• Powering Stellar Magnetism: Energy Transfers in Cyclic Dynamos of Sun-like Stars
• The magnetic field and multiple planets of the young dwarf AU~Mic
• The Evolving Magnetic Topology of $\tau$ Boötis
• The CoRoT target HD175726: an active star with weak solar-like oscillations
• Evidence for photometric activity cycles in 3203 Kepler stars
• Estimating activity cycles with probabilistic methods II. The Mount Wilson Ca H&K data
• On the Feasibility of Intense Radial Velocity Surveys for Earth-twin Discoveries
• Transition from axi- to nonaxisymmetric dynamo modes in spherical convection models of solar-like stars
• Direct observation of magnetic cycles in Sun-like stars
• Magnetic fields on young, moderately rotating Sun-like stars - I: HD~35296 and HD~29615
• Variable magnetic field geometry of the young sun HN Peg (HD 206860)
• Magnetised winds and their influence in the escaping upper atmosphere of HD 209458b
• On the sensitivity of magnetic cycles in global simulations of solar-like stars
• X-Ray, FUV, and UV Observations of alpha Centauri B: Determination of Long-term Magnetic Activity Cycle and Rotation Period
• Magnetic flux transport on active cool stars and starspot lifetimes
• Magnetic fields of young solar twins
• Coronal activity cycles in nearby G and K stars - XMM-Newton monitoring of 61 Cygni and Alpha Centauri
• Magnetic fields on young, moderately rotating Sun-like stars II. EK Draconis (HD 129333)
• A polarity reversal in the large-scale magnetic field of the rapidly rotating Sun HD 190771
• A photometric and spectroscopic survey of solar twin stars within 50 parsecs of the Sun: I. Atmospheric parameters and color similarity to the Sun
• An X-ray activity cycle on the young solar-like star $\epsilon \mathrm{Eridani}$
• Five Decades of Chromospheric Activity in 59 Sun-like Stars and New Maunder Minimum Candidate HD 166620
• The relation between stellar magnetic field geometry and chromospheric activity cycles II: The rapid 120 day magnetic cycle of Tau Bootis
• Direct evidence of a full dipole flip during the magnetic cycle of a sun-like star
• Evolution of solar and stellar dynamo theory
• Forward modelling of brightness variations in Sun-like stars I. Emergence and surface transport of magnetic flux
• Observing the simulations: Applying ZDI to 3D non-potential magnetic field simulations
• Stellar Cycles from Photometric Data: CoRoT Stars
• Quasi-periodic Gaussian Processes for stellar activity: from physical to kernel parameters
• Constraining the evolution of stellar rotation using solar twins
• Sounding stellar cycles with Kepler - I. Strategy for selecting targets
• A dynamo model of magnetic activity in solar-like stars with different rotational velocities
• iota Horologi, the first coronal activity cycle in a young solar-like star
• Measuring surface magnetic fields of red supergiant stars
• Magnetic field, activity and companions of V410 Tau
• The SPIRou Legacy Survey Rotation period of quiet M dwarfs from circular polarization in near-infrared spectral lines: I. The SPIRou APERO analysis
• Long-term Variability in the Length of the Solar Cycle
• Multi-instrumental view of magnetic fields and activity of $\epsilon$ Eridani with SPIRou, NARVAL, and TESS
• Monitoring the large-scale magnetic field of AD~Leo with SPIRou, ESPaDOnS and Narval. Toward a magnetic polarity reversal?
• Alpha effect due to buoyancy instability of a magnetic layer
• The Discovery of Solar-like Activity Cycles Beyond the End of the Main Sequence?
• Diagnosing large-scale stellar magnetic fields using PCA on spectropolarimetric data
• Observing and modeling the poloidal and toroidal fields of the solar dynamo
• Spectroscopic study of solar twins and analogues
• Evolution of the magnetic field of Betelgeuse from 2009 - 2017
• Magnetic activity cycles in solar-like stars: The cross-correlation technique of p-mode frequency shifts
• The magnetic field vector of the Sun-as-a-star. II. Evolution of the large-scale vector field through activity cycle 24
• The crucial role of surface magnetic fields for stellar dynamos: Epsilon Eridani, 61 Cygni A, and the Sun
• Constraining magnetic-activity modulations in 3~solar-like stars observed by CoRoT and NARVAL
• Zeeman-Doppler imaging of five young solar-type stars
• Three-dimensional imaging of convective cells in the photosphere of Betelgeuse
• Identifying solar-like magnetic cycles with Zeeman-Doppler-Imaging (ZDI)
• Influence of the Sun-like magnetic cycle on exoplanetary atmospheric escape
• 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
• Exploring cycle period and parity of stellar magnetic activity with dynamo modeling
• Dynamo modelling for cycle variability and occurrence of grand minima in Sun-like stars: Rotation rate dependence
• Determination of small-scale magnetic fields on Sun-like stars in the near-infrared using CRIRES${}^{+}$
• Time evolution of magnetic activity cycles in young suns: The curious case of kappa Ceti
• GONG p-mode parameters through two solar cycles
• The energetic particle environment of a GJ 436 b-like planet
• Evolution of solar wind sources and coronal rotation driven by the cyclic variation of the Sun's large-scale magnetic field

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• Zeeman Doppler Imaging of $\tau$Ceti: The Weakest Magnetic Field Detected in a Sun-like Star