1. Korea Astronomy and Space Science Institute, Daejeon 34055, Republic of Korea
2. Institute for Astrophysics, Chungbuk National University, Cheongju 28644, Republic of Korea
3. DTU Space, National Space Institute, Technical University of Denmark, Elektrovej 327, DK-2800 Lyngby, Denmark
4. Brorfelde Observatory, Observator Gyldenkernes Vej 7, DK-4340 Tølløse, Denmark