1. Center for Astrophysics | Harvard & Smithsonian, 60 Garden Street, Cambridge, MA 02138, USA
2. Black Hole Initiative, Harvard University, 20 Garden Street, Cambridge, MA 02138, USA
3. Massachusetts Institute of Technology Haystack Observatory, 99 Millstone Road, Westford, MA 01886, USA
4. National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan
5. California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA
6. Perimeter Institute for Theoretical Physics, 31 Caroline Street North, Waterloo, ON N2L 2Y5, Canada
7. Department of Physics and Astronomy, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada
8. Waterloo Centre for Astrophysics, University of Waterloo, Waterloo, ON N2L 3G1, Canada
9. Niels Bohr International Academy, Niels Bohr Institute, Blegdamsvej 17, 2100 Copenhagen, Denmark
10. CENTRA, Departamento de Física, Faculdade de Ciências, Instituto Superior Técnico—IST, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal
11. Astrophysics, Department of Physics, University of Oxford, Keble Road, Oxford OX1 3RH, UK
12. Department of Astronomy, University of Cape Town, Private Bag X3, Rondebosch 7701, South Africa
13. Institut für Theoretische Physik und Astrophysik, Universität Würzburg, Emil-Fischer-Strasse 31, D-97074 Würzburg, Germany
14. Institut für Theoretische Physik, Goethe Universität, Max-von-Laue-Str. 1, D-60438 Frankfurt, Germany
15. Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn, Germany
16. Department of History of Science, Harvard University, Cambridge, MA 02138, USA
17. Department of Physics, Harvard University, Cambridge, MA 02138, USA
18. Instituto de Astrofísica de Andalucía-CSIC, Glorieta de la Astronomía s/n, E-18008 Granada, Spain
19. Department of Physics, McGill University, 3600 rue University, Montreal, QC H3A 2T8, Canada
20. Trottier Space Institute at McGill, 3550 rue University, Montreal, QC H3A 2A7, Canada
21. Department of Physics and Astronomy, Purdue University, 525 Northwestern Avenue, West Lafayette, IN 47907, USA
22. Anton Pannekoek Institute for Astronomy, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
23. Gravitation and Astroparticle Physics Amsterdam (GRAPPA) Institute, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
24. Department of Astronomy, Yale University, 52 Hillhouse Avenue, New Haven, CT 06511, USA
25. Department of Physics, Yale University, P.O. Box 208121, New Haven, CT 06520, USA
26. Department of History, Princeton University, Dickinson Hall, Princeton, NJ 08544, USA
27. Mullard Space Science Laboratory, University College London, Holmbury St. Mary, Dorking, Surrey RH5 6NT, UK
28. Princeton Gravity Initiative, Princeton University, Jadwin Hall, Princeton, NJ 08544, USA
29. Lichtenberg Group for History and Philosophy of Physics, University of Bonn, 53113 Bonn, Germany
30. ICRAR, M468, The University of Western Australia, 35 Stirling Hwy, Crawley, WA 6009, Australia
31. Lebedev Physical Institute of the Russian Academy of Sciences, Leninsky prospekt 53, 119991 Moscow, Russia
32. Moscow Institute of Physics and Technology, Institutsky per. 9, 141700 Dolgoprudny, Russia
33. INAF-Istituto di Radioastronomia, Via P. Gobetti 101, I-40129 Bologna, Italy
34. Centre for the Study of Existential Risk, University of Cambridge, 16 Mill Lane, Cambridge CB2 1SB, UK
35. Freudenthal Institute, Utrecht University, 3584 CC Utrecht, The Netherlands
36. Descartes Centre for the History and Philosophy of the Sciences and the Humanities, Utrecht University, 3584 CC Utrecht, The Netherlands
37. Astronomy Department, Universidad de Concepción, Casilla 160-C, Concepción 4030000, Chile
38. CSIRO Astronomy and Space Science, P.O. Box 1130, Bentley, WA 6102, Australia
39. Observatorio Astronómico Nacional (IGN), Alfonso XII, 3 y 5, 28014 Madrid, Spain
40. Department of Astrophysics, Institute for Mathematics, Astrophysics and Particle Physics (IMAPP), Radboud University, P.O. Box 9010, 6500 GL Nijmegen, The Netherlands
41. McCoy Family Center for Ethics, Stanford University, Stanford, CA 94305, USA