1. Korea Astronomy and Space Science Institute, Daedeok-daero 776, Yuseong-gu, Daejeon 34055, Korea
2. University of Science and Technology, Gajeong-ro 217, Yuseong-gu, Daejeon 34113, Korea
3. Massachusetts Institute of Technology, Haystack Observatory, Route 40, Westford, MA 01886, USA
4. Black Hole Initiative, Harvard University, 20 Garden Street, Cambridge, MA 02138, USA
5. National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan
6. Graduate School of Science and Engineering, Kagoshima University, 1-21-35 Korimoto, Kagoshima, Kagoshima 890-0065, Japan
7. Center for Astronomy, Ibaraki University, 2-1-1 Bunkyo, Mito, Ibaraki 310-8512, Japan
8. Academic Support Center, Kogakuin University, 2665-1 Nakano, Hachioji, Tokyo 192-0015, Japan
9. Yonsei University, Yonsei-ro 50, Seodaemun-gu, Seoul 03722, Korea
10. Department of Astronomical Sciences, SOKENDAI (The Graduate University for Advanced Studies), Osawa 2-21-1, Mitaka, Tokyo 181-8588, Japan
11. Graduate School of Sciences and Technology for Innovation, Yamaguchi University, 1677-1 Yoshida, Yamaguchi, Yamaguchi 753-8511, Japan
12. The Research Institute for Time Studies, Yamaguchi University, 1677-1 Yoshida, Yamaguchi, Yamaguchi 753-8511, Japan