1. Department of Astronomy, University of Illinois at Urbana-Champaign , 1002 W. Green Street, Urbana, IL 61801, USA
2. Department of Physics and Astronomy, Michigan State University , 567 Wilson Road, East Lansing, MI 48824, USA
3. College of Science, George Mason University , Fairfax, VA 22030, USA
4. Lehrstuhl für Astronomie, Universität Würzburg , Emil-Fischer-Street 31, D-Würzburg 97074, Germany
5. CNRS, IRAP , F-31028 Toulouse CEDEX 4, France
6. GAHEC, Université de Toulouse, UPS-OMP, IRAP , F-31400 Toulouse, France
7. Space Science Division, Naval Research Laboratory , Washington, DC 20375-5352, USA
8. CRESST and X-ray Astrophysics Laboratory , NASA/GSFC, Greenbelt, MD 20771, USA
9. National Radio Astronomy Observatory, Domenici Science Operations Center , 1003 Lopezville Road, Socorro, NM 87801, USA
10. National Research Council, Herzberg Astronomy and Astrophysics , 717 White Lake Road, PO Box 248, Penticton, BC V2A 6J9, Canada
11. Department of Physics and Columbia Astrophysics Laboratory, Columbia University , New York, NY 10027, USA
12. Racah Institute of Physics, The Hebrew University , 9190401 Jerusalem, Israel
13. Tartu Observatory, University of Tartu , Tõravere, 61602 Tartumaa, Estonia
14. Center for Computational Astrophysics, Flatiron Institute , 162 5th Avenue, New York, NY 10010, USA
15. School of Physics & Astronomy, University of Leicester , Leicester LE1 7RH, UK
16. Department of Astronomy, University of Wisconsin–Madison , 475 N. Charter Street, Madison, WI 53706, USA
17. INAF – Padova , vicolo Osservatorio, 5, I-35122 Padova, Italy
18. Department of Astronomy and Mount Laguna Observatory, San Diego State University , San Diego, CA 92182, USA
19. Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo Institutes for Advanced Study, The University of Tokyo , Kashiwa, Chiba 277-8583, Japan
20. Department of Physics and Astronomy, University of North Carolina at Chapel Hill , Chapel Hill, NC 27599-3255, USA
21. AAVSO Observer
22. Remote observer of Burke-Gaffney Observatory, Abbey Ridge Observatory and Mini-Robotic Observatory , Canada
23. School of Physics and Astronomy, Rochester Institute of Technology , 84 Lomb Memorial Drive, Rochester, NY 14623, USA
24. Center for Backyard Astrophysics Illinois, Northbrook Meadow Observatory , 855 Fair Ln, Northbrook, IL 60062, USA
25. Center for Backyard Astrophysics Belgium , Walhostraat 1a, B-3401 Landen, Belgium
26. Center for Backyard Astrophysics Extremadura , e-EyE Astronomical Complex, E-06340 Fregenal de la Sierra, Spain
27. Burke-Gaffney Observatory, Saint Mary’s University , 923 Robie Street, Halifax, NS B3H 3C3, Canada