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Michael D. Johnson, Kazunori Akiyama, Rebecca Baturin, Bryan Bilyeu, Lindy Blackburn, Don Boroson, Alejandro Cardena-Avendano, Andrew Chael, Chi-kwan Chan, Dominic Chang, Peter Cheimets, Cathy Chou, Sheperd S. Doeleman, Joseph Farah, Peter Galison, Ronald Gamble, Charles F. Gammie, Zachary Gelles, Jose L. Gomez, Samuel E. Gralla, Paul Grimes, Shahar Hadar, Kari Haworth, Kazuhiro Hada, Michael H. Hecht, Mareki Honma, Janice Houston, Ben Hudson, Sara Issaoun, He Jia, Svetlana Jorstad, Jens Kauffmann, Yuri Kovalev, Leonid I. Gurvits, Peter Kurczynski, Robert Lafon, Alexandru Lupsasca, Robert Lehmensiek, Chung-Pei Ma, Daniel P. Marrone, Alan P. Marscher, Gary J. Melnick, Ramesh Narayan, Kotaro Niinuma, Scott C. Noble, Eric J. Palmer, Daniel C. Palumbo, Lenny Paritsky, Eliad Peretz, Dominic Pesce, Alexander Plavin, Eliot Quataert, Hannah Rana, Angelo Ricarte, Freek Roelofs, Katia Shtyrkova, Laura Sinclair, Jeffrey Small, Sridharan Tirupati Kumara, Ranjani Srinivasan, Andrew Strominger, Paul Tiede, Edward Tong, Jade Wang, Jonathan Weintroub, Maciek Wielgus, George Wong, Xinyue Alice Zhang
Abstract
We present the Black Hole Explorer (BHEX), a mission that will produce the sharpest images in the history of astronomy by extending submillimeter Very-Long-Baseline Interferometry (VLBI) to space. BHEX will discover and measure the bright and narrow "photon ring" that is predicted to exist in images of black holes, produced from light that has orbited the black hole before escaping. This discovery will expose universal features of a black hole's spacetime that are distinct from the complex astrophysics of the emitting plasma, allowing the first direct measurements of a supermassive black hole's spin. In addition to studying the properties of the nearby supermassive black holes M87∗ and Sgr A∗, BHEX will measure the properties of dozens of additional supermassive black holes, providing crucial insights into the processes that drive their creation and growth. BHEX will also connect these supermassive black holes to their relativistic jets, elucidating the power source for the brightest and most efficient engines in the universe. BHEX will address fundamental open questions in the physics and astrophysics of black holes that cannot be answered without submillimeter space VLBI. The mission is enabled by recent technological breakthroughs, including the development of ultra-high-speed downlink using laser communications, and it leverages billions of dollars of existing ground infrastructure. We present the motivation for BHEX, its science goals and associated requirements, and the pathway to launch within the next decade.
Johnson, M.
, Akiyama, K.
, Baturin, R.
, Bilyeu, B.
, Blackburn, L.
, Boroson, D.
, Cardena-Avendano, A.
, Chael, A.
, Chan, C.
, Chang, D.
, Cheimets, P.
, Chou, C.
, Doeleman, S.
, Farah, J.
, Galison, P.
, Gamble, R.
, Gammie, C.
, Gelles, Z.
, Gomez, J.
, Gralla, S.
, Grimes, P.
, Hadar, S.
, Haworth, K.
, Hada, K.
, Hecht, M.
, Honma, M.
, Houston, J.
, Hudson, B.
, Issaoun, S.
, Jia, H.
, Jorstad, S.
, Kauffmann, J.
, Kovalev, Y.
, Gurvits, L.
, Kurczynski, P.
, Lafon, R.
, Lupsasca, A.
, Lehmensiek, R.
, Ma, C.
, Marrone, D.
, Marscher, A.
, Melnick, G.
, Narayan, R.
, Niinuma, K.
, Noble, S.
, Palmer, E.
, Palumbo, D.
, Paritsky, L.
, Peretz, E.
, Pesce, D.
, Plavin, A.
, Quataert, E.
, Rana, H.
, Ricarte, A.
, Roelofs, F.
, Shtyrkova, K.
, Sinclair, L.
, Small, J.
, Kumara, S.
, Srinivasan, R.
, Strominger, A.
, Tiede, P.
, Tong, E.
, Wang, J.
, Weintroub, J.
, Wielgus, M.
, Wong, G.
and Zhang, X.
(2024),
The Black Hole Explorer: Motivation and Vision, SPIE Astronomical Telescopes + Instrumentation 2024, Yokohama, JP
(Accessed October 12, 2025)