The circumstellar environment of 55 Cnc: The super-Earth 55 Cnc e as a primary target for star-planet interactions

Abstract

Context. 55 Cancri hosts five known exoplanets, most notably the hot super-Earth 55 Cnc e, which is one of the hottest known transiting super-Earths. Aims. Due to the short orbital separation and host star brightness, 55 Cnc e provides one of the best opportunities for studying star-planet interactions (SPIs). We aim to understand possible SPIs in this system, which requires a detailed understanding of the stellar magnetic field and wind impinging on the planet. Methods. Using spectropolarimetric observations, and Zeeman Doppler Imaging, we derive a map of the large-scale stellar magnetic field. We then simulate the stellar wind starting from the magnetic field map, using a 3D MHD model. Results. The map of the large-scale stellar magnetic field we derive has an average strength of 3.4 G. The field has a mostly dipolar geometry, with the dipole tilted by 90 degrees with respect to the rotation axis, and dipolar strength of 5.8 G at the magnetic pole. The wind simulations based on this magnetic geometry lead us to conclude that 55 Cnc e orbits inside the Alfvén surface of the stellar wind, implying that effects from the planet on the wind can propagate back to the stellar surface and result in SPI.

arXiv commentAccepted for publication in A&A, 6 pages, 5 figures

References in corpus (22)

• The surprising magnetic topology of tauSco: fossil remnant or dynamo output?
• Least squares deconvolution of the stellar intensity and polarization spectra
• A map of the large day-night temperature gradient of a super-Earth exoplanet
• Hot Jupiters and Hot Spots: The Short- and Long-term Chromospheric Activity on Stars with Giant Planets
• Three-Dimensional MHD Simulation of the 2003 October 28 Coronal Mass Ejection: Comparison with LASCO Coronagraph Observations
• Suppression of Coronal Mass Ejections in active stars by an overlying large-scale magnetic field: A numerical study
• Variability in the super-Earth 55 Cnc e
• The evolution of surface magnetic fields in young solar-type stars II: The early main sequence (250-650 Myr)
• 55 Cancri: Stellar Astrophysical Parameters, a Planet in the Habitable Zone, and Implications for the Radius of a Transiting Super-Earth
• On the environment surrounding close-in exoplanets
• Magnetic field, differential rotation and activity of the hot-Jupiter hosting star HD 179949
• Search for an exosphere in sodium and calcium in the transmission spectrum of exoplanet 55 Cancri e
• Radii, masses, and ages of 18 bright stars using interferometry and new estimations of exoplanetary parameters
• Jovian Dust Streams: A monitor of Io's volcanic plume activity
• The solar wind in time: a change in the behaviour of older winds?
• Enhanced models for stellar Doppler noise reveal hints of a 13-year activity cycle of 55 Cancri
• MOVES I. The evolving magnetic field of the planet-hosting star HD189733
• Characterisation of the HD 219134 multi-planet system I. Observations of stellar magnetism, wind, and high-energy flux
• Evidence of magnetic star-planet interactions in the HD 189733 system from orbitally-phased Ca II K variations
• Time-variable electromagnetic star-planet interaction: The TRAPPIST-1 system as an exemplary case
• Estimating stellar wind parameters from low-resolution magnetograms
• The magnetic properties of the planet host star Kepler-78

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• The Effects of Magnetic Fields on Observational Signatures of Atmospheric Escape in Exoplanets: Double Tail Structures
• Alfvén-wave driven magnetic rotator winds from low-mass stars I: rotation dependences of magnetic braking and mass-loss rate
• Atmospheric compositions and observability of nitrogen dominated ultra-short period super-Earths
• Stellar versus Galactic: The intensity of cosmic rays at the evolving Earth and young exoplanets around Sun-like stars
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• Lambda And: A post-main sequence wind from a solar-mass star