Magnetic field evolution of the K2 dwarf V471 Tau

Abstract

Observations of the eclipsing binary system V471 Tau show that the time of the primary eclipses varies in an apparent periodic way. With growing evidence that the magnetically active K2 dwarf component might be responsible for driving the eclipse timing variations (ETVs), it is necessary to monitor the star throughout the predicted ~ 35 yr activity cycle that putatively fuels the observed ETVs. We contribute to this goal with this paper by analysing spectropolarimetric data obtained with ESPaDOnS at the Canada-France-Hawaii Telescope in December 2014 and January 2015. Using Zeeman-Doppler Imaging, we reconstruct the distribution of brightness inhomogeneities and large-scale magnetic field at the surface of the K2 dwarf. Compared to previous tomographic reconstructions of the star carried out with the same code, we probe a new phase of the ETVs cycle, offering new constraints for future works exploring whether a magnetic mechanism operating in the K2 dwarf star is indeed able to induce the observed ETVs of V471 Tau.

12 pages, 10 figures, submitted to MNRAS

References in corpus (16)

• Achieving better than 1 minute accuracy in the Heliocentric and Barycentric Julian Dates
• The surprising magnetic topology of tauSco: fossil remnant or dynamo output?
• A study of X-ray flares - I. Active late-type dwarfs
• The First Science Results from SPHERE: Disproving the Predicted Brown Dwarf around V471 Tau
• Spot patterns and differential rotation in the eclipsing pre-CV binary,V471 Tau
• The coronal structure of Speedy Mic - II: Prominence masses and off-disc emission
• MOST photometry and DDO spectroscopy of the eclipsing (white dwarf + red dwarf) binary V471 Tau
• Eclipse timing variation analysis of OGLE-IV eclipsing binaries toward the Galactic Bulge. I. Hierarchical triple system candidates
• Internal magnetic fields, spin-orbit coupling, and orbital period modulation in close binary systems
• Magnetic field and prominences of the young, solar-like, ultra-rapid rotator V530 Per
• A confined dynamo: magnetic activity of the K-dwarf component in the pre-cataclysmic binary system V471 Tauri
• Magnetic field and activity phenomena of the K2 dwarf V471 Tau
• Magnetic field of the eclipsing binary UV Piscium
• Revised Stellar Parameters for V471 Tau, A Post-common Envelope Binary in the Hyades
• Analysis of eclipsing binaries in multiple stellar systems: the case of V1200 Centauri
• Short-term variations of surface magnetism and prominences of the young Sun-like star V530 Per

Cited by in corpus (6)

• Origin of eclipsing time variations in Post-Common-Envelope binaries: role of the centrifugal force
• Variability of eclipse timing:the case of V471 Tauri
• Using Doppler Imaging to model stellar activity and search for planets around Sun-like stars
• Magnetic topologies of two weak-line T Tauri stars TAP 4 and TAP 40
• Effects of the centrifugal force in stellar dynamo simulations
• Inactive longitude and superflare in the active single-lined pre-main sequence binary V2279 Cyg