The director of the Event Horizon Telescope project, which recently dazzled science enthusiasts worldwide with its image of the black hole at the center of galaxy Messier 87 (M87), will receive the 2020 Lancelot M. Berkeley – New York Community Trust Prize for Meritorious Work in Astronomy [https://aas.org/grants-and-prizes/lancelot-m-berkeley-new-york-community-trust-prize-meritorious-work-astronomy]. Bestowed annually since 2011 by the American Astronomical Society (AAS) and supported by a grant from the New York Community Trust, the Berkeley prize includes a monetary award and an invitation to give the closing plenary lecture at the AAS winter meeting, often called the “Super Bowl of Astronomy.”

Sheperd S. Doeleman (Center for Astrophysics | Harvard & Smithsonian) is being honored with the 2020 Berkeley prize for his scientific contributions to, and his leadership of, the Event Horizon Telescope (EHT, https://eventhorizontelescope.org), a planet-scale array of ground-based radio telescopes stretching from Hawaii to Europe and from Greenland to the South Pole. Doeleman [https://projects.iq.harvard.edu/sdoeleman/bio] assembled an international team involving more than 200 scientists and engineers at 59 institutions in 20 countries to capture radio images of the close environments of supermassive black holes at the centers of galaxies. EHT’s targets are Sagittarius A* (pronounced “A star”), the 4-million-solar-mass black hole about 26,000 light-years away in the core of our own Milky Way galaxy, as well as the 6-billion-solar-mass behemoth about 55 million light-years away in the heart of the giant galaxy M87 in the Virgo cluster. Doeleman and his team published their initial results, on the second of those targets, in six papers (“First M87 Event Horizon Telescope Results I-VI”) in the Astrophysical Journal Letters [https://iopscience.iop.org/journal/2041-8205/page/Focus_on_EHT] on 10 April 2019, covering the gamut from observations through images to interpretation.

The EHT is named for the event horizon, the boundary of the region around a black hole within which the escape velocity exceeds the speed of light. The event horizon and the volume it encloses are by definition invisible, but when a black hole is surrounded by a luminous disk of hot gas, as is the case in both the Milky Way and M87, it should be possible to see the gas shining just outside the dark region bounded by the event horizon, sometimes called the “shadow” of the black hole but more properly referred to as its silhouette. Yet even for the gargantuan black holes at the centers of our galaxy and M87, the angular size of that silhouette is only about a hundred-millionth of a degree. Only a short-wavelength radio telescope the size of Earth can detect something that tiny, and that’s why we didn’t see an actual image of a black hole until the advent of the EHT, which combines 1.3-mm radio signals from widely separated antennas into the equivalent of a single planet-size telescope, a technique called very-long-baseline interferometry (VLBI, https://www.skyandtelescope.com/astronomy-blogs/black-hole-files/how-does-very-long-baseline-interferometry-work). Doeleman launched the EHT effort a decade ago after using VLBI to make the first detections of horizon-scale structures very close to the Sgr A* and M87 black holes. He then led the ALMA Phasing Project, which enabled the 66 antennas of the Atacama Large Millimeter/submillimeter Array in Chile to work in concert as a single very sensitive VLBI station within the global EHT network.

Each year the three AAS Vice-Presidents, in consultation with the Editor in Chief of the AAS journals, select the Berkeley prize winner for meritorious research published within the preceding 12 months. Reacting to VP Michael Strauss’s email announcing his selection as the 2020 Berkeley prize recipient, Doeleman said, “This is wonderful news. The credit truly belongs to the entire EHT collaboration. It has been a magnificent collective effort by an extraordinary worldwide team of talented scientists.” He will give his prize lecture on Wednesday afternoon, 8 January 2020, during the 235th AAS meeting [https://aas.org/meetings/aas235] at the Hawaii Convention Center in Honolulu.

Shep Doeleman received his bachelor’s degree from Reed College in 1986 and then spent a year in Antarctica conducting space-science experiments at McMurdo Station on the Ross Ice Shelf. With an appreciation for the challenges and rewards of instrumental work in difficult circumstances, he pursued his doctorate in astrophysics at the Massachusetts Institute of Technology
(MIT). After a research visit to the Max Planck Institute for Radio Astronomy through a DAAD German Academic Exchange grant, he returned to MIT Haystack Observatory to develop a research program of millimeter/submillimeter-wavelength VLBI and eventually served as the observatory’s assistant director. He was a Guggenheim Fellow in 2012 and moved to the Harvard University that same year. He is now a Harvard Senior Research Fellow and Astronomer at the Smithsonian Astrophysical Observatory. In addition to directing the EHT, Doeleman is a founding member and Assistant Director for Observation of Harvard’s interdisciplinary Black Hole Initiative [https://bhi.fas.harvard.edu].

The American Astronomical Society (AAS), established in 1899, is the major organization of professional astronomers in North America. Its membership (approx. 7,500) also includes physicists, mathematicians, geologists, engineers, and others whose research interests lie within the broad spectrum of subjects now comprising the astronomical sciences. The mission of the American Astronomical Society is to enhance and share humanity’s scientific understanding of the universe, which it achieves through publishing, meeting organization, education and outreach, and training and professional development.