Oscillations in the habitable zone around α Centauri B
Version of Record online: 2 MAR 2012
© 2012 The Author Monthly Notices of the Royal Astronomical Society © 2012 RAS
Monthly Notices of the Royal Astronomical Society
Volume 422, Issue 2, pages 1241–1249, May 2012
How to Cite
Forgan, D. (2012), Oscillations in the habitable zone around α Centauri B. Monthly Notices of the Royal Astronomical Society, 422: 1241–1249. doi: 10.1111/j.1365-2966.2012.20698.x
- Issue online: 25 APR 2012
- Version of Record online: 2 MAR 2012
- Accepted 2012 February 4. Received 2012 February 3; in original form 2011 December 21
- radiative transfer;
- planets and satellites: general
The α Cen AB system is an attractive one for radial velocity observations to detect potential exoplanets. The high metallicity of both α Cen A and B suggests that they could have possessed circumstellar discs capable of forming planets. As the closest star system to the Sun, with well over a century of accurate astrometric measurements (and α Cen B exhibiting low chromospheric activity), high-precision surveys of α Cen B’s potential exoplanetary system are possible with relatively cheap instrumentation. Authors studying habitability in this system typically adopt habitable zones (HZs) based on global radiative balance models that neglect the radiative perturbations of α Cen A.
We investigate the habitability of planets around α Cen B using one-dimensional latitudinal energy balance models (LEBMs), which fully incorporate the presence of α Cen A as a means of astronomically forcing terrestrial planet climates. We find that the extent of the HZ is relatively unchanged by the presence of α Cen A, but there are variations in fractional habitability for planets orbiting at the boundaries of the zone due to α Cen A, even in the case of zero eccentricity. Temperature oscillations of a few K can be observed at all planetary orbits, the strength of which varies with the planet’s ocean fraction and obliquity.