Harvard–Smithsonian Center for Astrophysics


The Center for Astrophysics | Harvard & Smithsonian is an astrophysics research institute jointly operated by the Harvard College Observatory and Smithsonian Astrophysical Observatory. Founded in 1973 and headquartered in Cambridge, Massachusetts, the CfA leads a broad program of research in astronomy, astrophysics, Earth and space sciences, as well as science education. The CfA either leads or participates in the development and operations of more than fifteen ground- and space-based astronomical research observatories across the electromagnetic spectrum, including the forthcoming Giant Magellan Telescope and the Chandra X-ray Observatory, one of NASA's Great Observatories.
Hosting more than 850 scientists, engineers, and support staff, the CfA is among the largest astronomical research institutes in the world. Its projects have included Nobel Prize-winning advances in cosmology and high energy astrophysics, the discovery of many exoplanets, and the first image of a black hole. The CfA also serves a major role in the global astrophysics research community: the CfA's Astrophysics Data System, for example, has been universally adopted as the world's online database of astronomy and physics papers. Known for most of its history as the "Harvard-Smithsonian Center for Astrophysics", the CfA rebranded in 2018 to its current name in an effort to reflect its unique status as a joint collaboration between Harvard University and the Smithsonian Institution. The CfA's current Director is Charles R. Alcock, who succeeds Irwin I. Shapiro and George B. Field.

History of the CfA

The Center for Astrophysics | Harvard & Smithsonian is not formally an independent legal organization, but rather an operated under a Memorandum of Understanding between Harvard University and the Smithsonian Institution. This collaboration was formalized on July 1, 1973, with the goal of coordinating the related research activities of the Harvard College Observatory and the Smithsonian Astrophysical Observatory under the leadership of a single , and housed within the same on the Harvard campus in Cambridge, Massachusetts. The CfA's history is therefore also that of the two fully independent organizations that comprise it. With a combined lifetime of more than 300 years, HCO and SAO have been host to major milestones in astronomical history that predate the CfA's founding. These are briefly summarized below.

History of the Smithsonian Astrophysical Observatory (SAO)

, the third Secretary of the Smithsonian, founded the Smithsonian Astrophysical Observatory on the south yard of the Smithsonian Castle on March 1,1890. The Astrophysical Observatory's initial, primary purpose was to "record the amount and character of the Sun's heat". Charles Greeley Abbot was named SAO's first director, and the observatory operated solar telescopes to take daily measurements of the Sun's intensity in different regions of the optical electromagnetic spectrum. In doing so, the observatory enabled Abbot to make critical refinements to the Solar constant, as well as to serendipitously discover Solar variability. It is likely that SAO's early history as a solar observatory was part of the inspiration behind the Smithsonian's , designed in 1965 by Crimilda Pontes.
In 1955, the scientific headquarters of SAO moved from Washington, D.C. to Cambridge, Massachusetts to affiliate with the Harvard College Observatory. Fred Lawrence Whipple, then the chairman of the Harvard Astronomy Department, was named the new director of SAO. The collaborative relationship between SAO and HCO therefore predates the official creation of the CfA by 18 years. SAO's move to Harvard's campus also resulted in a rapid expansion of its research program. Following the launch of Sputnik in 1957, SAO accepted a national challenge to create a worldwide satellite-tracking network, collaborating with the United States Air Force on Project Space Track.
With the creation of NASA the following year and throughout the space race, SAO led major efforts in the development of orbiting observatories and large ground-based telescopes, laboratory and theoretical astrophysics, as well as the application of computers to astrophysical problems.

History of Harvard College Observatory (HCO)

Partly in response to renewed public interest in astronomy following the 1835 return of Halley's Comet, the Harvard College Observatory was founded in 1839, when the Harvard Corporation appointed William Cranch Bond as an "Astronomical Observer to the University". For its first four years of operation, the observatory was situated at the Dana-Palmer House near Harvard Yard, and consisted of little more than three small telescopes and an astronomical clock. In his 1840 book recounting the history of the college, then Harvard President Josiah Quincy III noted that "...there is wanted a reflecting telescope equatorially mounted...". This telescope, the 15-inch "", opened seven years later at the top of Observatory Hill in Cambridge. The telescope was the largest in the United States from 1847 until 1867. William Bond and pioneer photographer John Adams Whipple used the Great Refractor to produce the first clear Daguerrotypes of the Moon. Bond and his son, George Phillips Bond, used it to discover Saturn's 8th moon, Hyperion.
Under the directorship of Edward Charles Pickering from 1877 to 1919, the observatory became the world's major producer of stellar spectra and magnitudes, established in Peru, and applied mass-production methods to the analysis of data. It was during this time that HCO became host to a series of major discoveries in astronomical history, powered by the Observatory's so-called "Computers". These "Computers" included Williamina Fleming, Annie Jump Cannon, Henrietta Swan Leavitt, Florence Cushman and Antonia Maury, all widely recognized today as major figures in scientific history. Henrietta Swan Leavitt, for example, discovered the so-called period-luminosity relation for Classical Cepheid variable stars, establishing the first major "standard candle" with which to measure the distance to galaxies. Now called "Leavitt's Law", the discovery is regarded as one of the most foundational and important in the history of astronomy; astronomers like Edwin Hubble, for example, would later use Leavitt's Law to establish that the Universe is expanding, the primary piece of evidence for the Big Bang model.
Upon Pickering's retirement in 1921, the Directorship of HCO fell to Harlow Shapley. This era of the observatory was made famous by the work of Cecelia Payne-Gaposchkin, who became the first woman to earn a Ph.D. in astronomy from Radcliffe College. Payne-Gapochkin's 1925 thesis proposed that stars were composed primarily of hydrogen and helium, an idea thought ridiculous at the time. Between Shapley's tenure and the formation of the CfA, the observatory was directed by Donald H. Menzel and then Leo Goldberg, both of whom maintained widely recognized programs in solar and stellar astrophysics. Menzel played a major role in encouraging the Smithsonian Astrophysical Observatory to move to Cambridge and collaborate more closely with HCO.

Joint history as the Center for Astrophysics (CfA)

The collaborative foundation for what would ultimately give rise to the Center for Astrophysics began with SAO's move to Cambridge in 1955. Fred Whipple, who was already chair of the Harvard Astronomy Department, was named SAO's new director at the start of this new era; an early test of the model for a unified Directorship across HCO and SAO. The following 18 years would see the two independent entities merge ever closer together, operating effectively as one large research center.
This joint relationship was formalized as the new Harvard–Smithsonian Center for Astrophysics on July 1, 1973. George B. Field, then affiliated with Berkeley, was appointed as its first Director. That same year, a new astronomical journal, the "CfA Preprint Series" was created, and a CfA/SAO instrument flying aboard Skylab discovered coronal holes on the Sun. The founding of the CfA also coincided with the birth of X-ray astronomy as a new, major field that was largely dominated by CfA scientists in its early years. Riccardo Giacconi, regarded as the "father of X-ray astronomy", founded the within the new CfA by moving most of his research group to SAO in 1973. That group would later go on to launch the Einstein Observatory in 1976, and ultimately lead the proposals and development of what would become the Chandra X-ray Observatory. Chandra, the second of NASA's Great Observatories and still the most powerful X-ray telescope in history, continues operations today as part of the CfA's . Giacconi would later win the 2002 Nobel Prize in Physics for his foundational work in X-ray astronomy.
Shortly after the launch of the Einstein Observatory, the CfA's Steven Weinberg won the 1979 Nobel Prize in Physics for his work on electroweak unification. The following decade saw the start of the landmark CfA Redshift Survey, as well as the release of the "", a highly influential Astronomy & Astrophysics Decadal Survey chaired by the outgoing CfA Director George Field. He would be replaced in 1982 by Irwin Shapiro, who during his tenure as Director oversaw the expansion of the CfA's observing facilities around the world, including the newly named Fred Lawrence Whipple Observatory, the Infrared Telescope aboard the Space Shuttle, the 6.5-meter Multiple Mirror Telescope, the SOHO satellite, and the launch of Chandra in 1999. CfA-led discoveries throughout this period include canonical work on Supernova 1987A, the "CfA2 Great Wall", the best-yet evidence for supermassive black holes, and the for an extrasolar planet.
The 1990s also saw the CfA unwittingly play a major role in the history of computer science and the internet: in 1990, SAO developed , one of the world's first X11-based applications made publicly available. During this time, scientists at the CfA also began work on what would become the Astrophysics Data System, one of the world's first online databases of research papers. By 1993, the ADS was running the first routine transatlantic queries between databases, a foundational aspect of the internet today.

The CfA Today

Research at the CfA

, known for a number of major works related to massive compact halo objects, was named the third director of the CfA in 2004. Today Alcock overseas one of the largest and most productive astronomical institutes in the world, with more than 850 staff and an annual budget in excess of $100M USD. The Harvard , housed within the CfA, maintains a continual complement of approximately 60 Ph.D. students, more than 100 postdoctoral researchers, and roughly 25 undergraduate majors in astronomy and astrophysics from Harvard College. SAO, meanwhile, hosts a long-running and highly rated REU Summer Intern program as well as many visiting graduate students. The CfA estimates that roughly 10% of the professional astrophysics community in the United States spent at least a portion of their career or education there.
The CfA is either a lead or major partner in the operations of the Fred Lawrence Whipple Observatory, the Submillimeter Array, MMT Observatory, the South Pole Telescope, VERITAS, and a number of other smaller ground-based telescopes. The CfA's includes the construction of the Giant Magellan Telescope as a driving priority for the Center.
Along with the Chandra X-ray Observatory, the CfA plays a central role in a number of space-based observing facilities, including the recently launched Parker Solar Probe, Kepler Space Telescope, the Solar Dynamics Observatory, and HINODE. The CfA, via the Smithsonian Astrophysical Observatory, recently played a major role in the Lynx X-ray Observatory, a NASA-Funded Large Mission Concept Study commissioned as part of the . If launched, Lynx would be the most powerful X-ray observatory constructed to date, enabling order-of-magnitude advances in capability over Chandra.
SAO is one of the 13 stakeholder institutes for the Event Horizon Telescope Board, and the CfA hosts its Array Operations Center. In 2019, the project revealed the . The result is widely regarded as a triumph not only of observational astronomy, but of its intersection with theoretical astrophysics. Union of the observational and theoretical subfields of astrophysics has been a major focus of the CfA since its founding.
In 2018, the CfA rebranded, changing its official name to the "Center for Astrophysics | Harvard & Smithsonian" in an effort to reflect its unique status as a joint collaboration between Harvard University and the Smithsonian Institution. Today, the CfA receives roughly 70% of its funding from NASA, 22% from Smithsonian federal funds, and 4% from the National Science Foundation. The remaining 4% comes from contributors including the United States Department of Energy, the Annenberg Foundation, as well as other gifts and endowments.

Organizational Structure

Research across the CfA is organized into six divisions and seven research centers:

Scientific Divisions within the CfA

The CfA is also host to the , large and facilities, the , the , the world's largest database of astronomy and physics papers, and the .

Observatories operated with CfA participation

Ground-based observatories