Modeling the radio signature of the orbital parameters, rotation, and magnetic field of exoplanets
1 LASP, University of Colorado at Boulder, USA
2 LESIA, Observatoire de Paris CNRS, UPMC, Univ. Paris 7, France
3 LATMOS-IPSL, Université Versailles St.-Quentin, CNRS/INSU, France
Received: 14 January 2011
Accepted: 16 March 2011
Context. Since the first extra-solar planet discovery in 1995, several hundreds of these planets have been discovered. Most are hot Jupiters, i.e. massive planets orbiting close to their star. These planets may be powerful radio emitters.
Aims. We simulate the radio dynamic spectra resulting from various interaction models between an exoplanet and its parent star, i.e. exoplanet-induced stellar emission and three variants of the exoplanet’s magnetospheric auroral radio emission (full auroral oval, active sector fixed in longitude, and active sector fixed in local time).
Methods. We show the physical information about the system that can be drawn from radio observations, and how this can be achieved. This information includes the magnetic field strength and the rotation period of the emitting body (planet or star), the orbital period, the orbit’s inclination, and the magnetic field tilt relative to the rotation axis or offset relative to the center of the planet. For most of these parameters, radio observations provide a unique means of measuring them.
Results. Our results should provide the proper framework of analysis and interpretation for future detections of radio emissions from exoplanetary systems – or from magnetic white dwarf-planet or white dwarf-brown dwarf systems –, that are expected to commence soon as part of extensive programs at large radiotelescopes such as LOFAR, UTR2 or the GMRT. Our methodology can be easily adapted to simulate specific observations, once effective detection is achieved.
Key words: planet-star interactions / planets and satellites: aurorae / radio continuum: planetary systems
© ESO, 2011