1. Leibniz Institute for Astrophysics Potsdam (AIP), An der Sternwarte 16, 14482 Potsdam, Germany
2. Institute for Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Str. 24/25, 14476 Potsdam, Germany
3. Department of Physics and Astronomy, Dartmouth College, Hanover, NH 03755, USA
4. University of Colorado Boulder, Laboratory for Atmospheric and Space Physics, 3665 Discovery Drive, Boulder CO, 80303, USA
5. Department of Astronomy, University of Washington, Seattle, WA 98195, USA
6. Instituto de Astrofísica de Canarias (IAC), 38205 La Laguna, Tenerife, Spain
7. Departamento de Astrofísica, Universidad de La Laguna (ULL), 38206, La Laguna, Tenerife, Spain