Magnetic coupling of planets and small bodies with a pulsar wind
LUTH, Observatoire de Paris, CNRS, Unviersité Paris Diderot, 5 place Jules Janssen, 92190 Meudon, France
2 Observatoire Astronomique, Université de Strasbourg, 11 rue de l’Université, 67000 Strasbourg, France
Received: 17 January 2011
Accepted: 25 May 2011
Aims. We investigate the electromagnetic interaction of a relativistic stellar wind with a planet or a smaller body in orbit around the star. This may be relevant to objects orbiting a pulsar that are expected to hold a planetary system, such as PSR B1257+12 and PSR B1620-26, or to pulsars with suspected asteroids or comets.
Methods. We extend the theory of Alfvén wings to relativistic winds.
Results. When the wind is relativistic but slower than the total Alfvén speed, a system of electric currents carried by a stationary Alfvénic structure is driven by the planet or by its surroundings.For an Earth-like planet around a “standard” second pulsar, the associated current can reach the same magnitude as the Goldreich-Julian current that powers the pulsar’s magnetosphere.
Key words: plasmas / relativistic processes / methods: analytical / pulsars: general / planets and satellites: dynamical evolution and stability / planet-star interactions
© ESO, 2011