Geomagnetic properties of Proxima Centauri b analogues

Geomagnetic properties of Proxima Centauri b analogues

Authors:

Zuluaga et al

Abstract:

The recent discovery of a planet around the closest star, Proxima Centauri, could represent a quantum leap on the testability of models in exoplanet sciences. Unlike any other discovered exoplanet, models of planetary processes in Proxima b could be contrasted against near future telescopic observations and far future in-situ measurements. In this paper we study the geomagnetic properties of Proxima b analogues, namely, solid planets with masses close but larger than Earth's mass, periods of rotation of several days and habitable surface conditions. Assuming different planetary masses, bulk compositions and periods of rotations, we calculate for each planetary analogue its radius, heat flux, time of inner core formation, dynamo lifetime and minimum dipole magnetic moment. We find that most (≳70\%) Proxima b analogues develop intrinsic dynamos that last at least 3 Gyr, although only half of them are older than the present age of the host star (4−6 Gyr). Relying in our planetary evolution models, we predict with a 70% confidence level that Proxima b will be an earth-like planet with mass and radius 1.3