1. Stellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C, Denmark
2. Dipartimento di Fisica e Astronomia, Università degli Studi di Bologna, Via Gobetti 93/2, I-40129 Bologna, Italy
3. Max Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg, Germany
4. Lund Observatory, Department of Astronomy and Theoretical Physics, Box 43, SE-221 00 Lund, Sweden
5. INAF-Astronomical Observatory of Abruzzo, Via M. Maggini sn, I-64100 Teramo, Italy
6. INFN - Sezione di Pisa, Largo Pontecorvo 3, I-56127 Pisa, Italy
7. Instituto de Ciencias del Espacio (ICE, CSIC), Campus UAB, Carrer de Can Magrans, s/n, E-08193 Cerdanyola del Valles, Spain
8. Institut d’Estudis Espacials de Catalunya (IEEC), Gran Capita 4, E-08034, Barcelona, Spain
9. Research School of Astronomy and Astrophysics, Mount Stromlo Observatory, The Australian National University, ACT 2611, Australia
10. School of Physics and Astronomy, University of Birmingham, B15 2TT Birmingham, UK
11. Physics Department, Wichita State University, KS 67260-0032 Wichita, USA
12. Max-Planck-Institut für Astrophysics, Karl Schwarzschild Strasse 1, D-85748, Garching, Germany
13. Sydney Institute for Astronomy (SIfA), School of Physics, University of Sydney, NSW 2006, Australia