1. Lund Observatory, Department of Astronomy and Theoretical Physics, Lund University, Box 43, SE-221 00 Lund, Sweden
2. Universidad Autónoma de Madrid, Departamento de Física Teórica, E-28049 Madrid, Spain
3. Department of Physics, University of Warwick, Coventry CV4 7AL, UK
4. Centre for Exoplanets and Habitability, University of Warwick, Coventry CV4 7AL, UK
5. Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK