Breezing through the space environment of Barnard's Star b

Abstract

A physically realistic stellar wind model based on Alfvén wave dissipation has been used to simulate the wind from Barnard's Star and to estimate the conditions at the location of its recently discovered planetary companion. Such models require knowledge of the stellar surface magnetic field that is currently unknown for Barnard's Star. We circumvent this by considering the observed field distributions of three different stars that constitute admissible magnetic proxies of this object. Under these considerations, Barnard's Star b experiences less intense wind pressure than the much more close-in planet Proxima~b and the planets of the TRAPPIST-1 system. The milder wind conditions are more a result of its much greater orbital distance rather than in differences in the surface magnetic field strengths of the host stars. The dynamic pressure experienced by the planet is comparable to present-day Earth values, but it can undergo variations by factors of several during current sheet crossings in each orbit. The magnetospause standoff distance would be $\sim$\,$20-40$\,\% smaller than that of the Earth for an equivalent planetary magnetic field strength.

J. D. Alvarado-Gómez & C. Garraffo contributed equally to this work. 8 Pages, 4 Figures. Accepted to The Astrophysical Journal Letters

References in corpus (14)

• Planet formation around stars of various masses: The snow line and the frequency of giant planets
• Large-scale magnetic topologies of late M dwarfs
• Simulations of dynamo action in fully convective stars
• Toroidal versus poloidal magnetic fields in Sun-like stars: a rotation threshold
• The effect of magnetic topology on thermally-driven winds: towards a general formulation of the braking law
• Stellar Winds on the Main-Sequence II: the Evolution of Rotation and Winds
• Solar-type dynamo behaviour in fully convective stars without a tachocline
• The Space Weather of Proxima Centauri b
• Magnetospheric Structure and Atmospheric Joule Heating of Habitable Planets Orbiting M-dwarf Stars
• On the environment surrounding close-in exoplanets
• The Threatening Environment of the TRAPPIST-1 Planets
• Stellar Winds on the Main-Sequence I: Wind Model
• Simulating the environment around planet-hosting stars - II. Stellar winds and inner astrospheres
• Exoplanets as probes of the winds of host stars: the case of the M dwarf GJ 436

Cited by in corpus (11)

• New Observational Constraints on the Winds of M Dwarf Stars
• Simulating the Space Weather in the AU Mic System: Stellar Winds and Extreme Coronal Mass Ejections
• Tuning the Exo-Space Weather Radio for Stellar Coronal Mass Ejections
• Stellar Winds Drive Strong Variations in Exoplanet Evaporative Outflows and Transit Absorption Signatures
• Radio masers on WX UMa: hints of a Neptune-sized planet, or magnetospheric reconnection?
• Lambda And: A post-main sequence wind from a solar-mass star
• Coronal mass ejections and type II radio emission variability during a magnetic cycle on the solar-type star $\epsilon$ Eridani
• Revisiting the space weather environment of Proxima Centauri b
• The Space Environment and Atmospheric Joule Heating of the Habitable Zone Exoplanet TOI700-d
• Far beyond the Sun: II. Probing the stellar magnetism of the young Sun ι Horologii from the photosphere to its corona
• The most sensitive SETI observations toward Barnard's star with FAST