The Smithsonian Astrophysical Observatory (SAO) is a research institute of the

Smithsonian Institution The Smithsonian Institution ( ), or simply the Smithsonian, is a group of museums and education and research centers, the largest such complex in the world, created by the U.S. government "for the increase and diffusion of knowledge". Founded ...

, concentrating on astrophysical studies including

galactic Galactic is an American jam band from New Orleans, Louisiana. Origins and background Formed in 1994 as an octet (under the name Galactic Prophylactic) and including singer Chris Lane and guitarist Rob Gowen, the group was soon pared down to a ...

and extragalactic astronomy,

cosmology Cosmology () is a branch of physics and metaphysics dealing with the nature of the universe. The term ''cosmology'' was first used in English in 1656 in Thomas Blount's ''Glossographia'', and in 1731 taken up in Latin by German philosopher ...

, solar, earth and planetary sciences,

theory A theory is a rational type of abstract thinking about a phenomenon, or the results of such thinking. The process of contemplative and rational thinking is often associated with such processes as observational study or research. Theories may be ...

and instrumentation, using observations at

wavelengths In physics, the wavelength is the spatial period of a periodic wave—the distance over which the wave's shape repeats. It is the distance between consecutive corresponding points of the same phase on the wave, such as two adjacent crests, tr ...

from the highest energy

gamma rays A gamma ray, also known as gamma radiation (symbol γ or \gamma), is a penetrating form of electromagnetic radiation arising from the radioactive decay of atomic nuclei. It consists of the shortest wavelength electromagnetic waves, typically ...

to the

radio Radio is the technology of signaling and communicating using radio waves. Radio waves are electromagnetic waves of frequency between 30 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transmit ...

, along with

gravitational waves Gravitational waves are waves of the intensity of gravity generated by the accelerated masses of an orbital binary system that propagate as waves outward from their source at the speed of light. They were first proposed by Oliver Heaviside in 1 ...

. Established in

Washington, D.C. ) , image_skyline = , image_caption = Clockwise from top left: the Washington Monument and Lincoln Memorial on the National Mall, United States Capitol, Logan Circle, Jefferson Memorial, White House, Adams Morgan, ...

, in

1890 Events January–March * January 1 ** The Kingdom of Italy establishes Eritrea as its colony, in the Horn of Africa. ** In Michigan, the wooden steamer ''Mackinaw'' burns in a fire on the Black River. * January 2 ** The steamship ...

, the SAO moved its headquarters in 1955 to

Cambridge, Massachusetts Cambridge ( ) is a city in Middlesex County, Massachusetts, United States. As part of the Boston metropolitan area, the cities population of the 2020 U.S. census was 118,403, making it the fourth most populous city in the state, behind Boston, ...

, where its research is a collaboration with the

Harvard College Observatory The Harvard College Observatory (HCO) is an institution managing a complex of buildings and multiple instruments used for astronomical research by the Harvard University Department of Astronomy. It is located in Cambridge, Massachusetts, United St ...

(HCO) and the

Harvard University Harvard University is a private Ivy League research university in Cambridge, Massachusetts. Founded in 1636 as Harvard College and named for its first benefactor, the Puritan clergyman John Harvard, it is the oldest institution of higher le ...

Department of Astronomy. In 1973, the Smithsonian and Harvard formalized the collaboration as the Center for Astrophysics , Harvard & Smithsonian (CfA) under a single Director.

History

Samuel Pierpont Langley Samuel Pierpont Langley (August 22, 1834 – February 27, 1906) was an American aviation pioneer, astronomer and physicist who invented the bolometer. He was the third secretary of the Smithsonian Institution and a professor of astronomy a ...

, the third

Secretary of the Smithsonian The Smithsonian Institution ( ), or simply the Smithsonian, is a group of museums and education and Research institute, research centers, the largest such complex in the world, created by the Federal government of the United States, U.S. govern ...

, founded the Smithsonian Astrophysical Observatory on the south yard of the

Smithsonian Castle The Smithsonian Institution Building, located near the National Mall in Washington, D.C. behind the National Museum of African Art and the Sackler Gallery, houses the Smithsonian Institution's administrative offices and information center. The ...

(on the U.S.

National Mall The National Mall is a Landscape architecture, landscaped park near the Downtown, Washington, D.C., downtown area of Washington, D.C., the capital city of the United States. It contains and borders a number of museums of the Smithsonian Institut ...

) on March 1,

. The Astrophysical Observatory's initial, primary purpose was to "''record the amount and character of the Sun's heat''".

Charles Greeley Abbot Charles Greeley Abbot (May 31, 1872 – December 17, 1973) was an American astrophysicist and the fifth secretary of the Smithsonian Institution, serving from 1928 until 1944. Abbot went from being director of the Smithsonian Astrophysical Obser ...

was named SAO's first director, and the observatory operated solar telescopes to take daily measurements of the

Sun The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared radi ...

'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 The solar constant (''GSC'') is a flux density measuring mean solar electromagnetic radiation (total solar irradiance) per unit area. It is measured on a surface perpendicular to the rays, one astronomical unit (au) from the Sun (roughly the ...

, as well as to serendipitously discover Solar variability. It is likely that SAO's early history as a

solar observatory A solar observatory is an observatory that specializes in monitoring the Sun. As such, they usually have one or more solar telescopes. The Einstein Tower was a solar observatory in the Albert Einstein Science Park in Potsdam, Germany. Solar ...

was part of the inspiration behind the Smithsonian'
"sunburst" logo
designed in 1965 by Crimilda Pontes. In 1955, the scientific headquarters of SAO moved from

to affiliate with the

(HCO).

Fred Lawrence Whipple Fred Lawrence Whipple (November 5, 1906 – August 30, 2004) was an American astronomer, who worked at the Harvard College Observatory for more than 70 years. Amongst his achievements were asteroid and comet discoveries, the " dirty snowball" h ...

, 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'' (the world's first human-made satellite) in 1957, SAO accepted a national challenge to create a worldwide satellite-tracking network, collaborating with the

United States Air Force The United States Air Force (USAF) is the air service branch of the United States Armed Forces, and is one of the eight uniformed services of the United States. Originally created on 1 August 1907, as a part of the United States Army Signal ...

on Project Space Track. With the creation of

NASA The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeeding t ...

the following year and throughout the

space race The Space Race was a 20th-century competition between two Cold War rivals, the United States and the Soviet Union, to achieve superior spaceflight capability. It had its origins in the ballistic missile-based nuclear arms race between the tw ...

, SAO led major efforts in the development of orbiting observatories and large

ground-based telescope The following are lists of devices categorized as types of telescopes or devices associated with telescopes. They are broken into major classifications with many variations due to professional, amateur, and commercial sub-types. Telescopes can be ...

s, laboratory and

theoretical astrophysics Astrophysics is a science that employs the methods and principles of physics and chemistry in the study of astronomical objects and phenomena. As one of the founders of the discipline said, Astrophysics "seeks to ascertain the nature of the hea ...

, as well as the application of computers to astrophysical problems.

Remote stations

SAO has operated a number of remote stations over the years.

SAO Today

The current director of the SAO is Lisa Kewley (2022 to present). There are currently about 170 research staff working at the SAO, including affiliated research staff. In addition, the SAO has about 120 postdoctoral researchers/fellows working in five competitive, associated fellowship programs: CfA, Clay, SMA, ITAMP, and Leon Van Speybroeck, or in support of a contract or grant. (Additional postdocs do research via Harvard fellowship programs or national/international fellowship awards); about 40% of the postdoctoral community are women and about 12% are from minority populations. SAO scientists can supervise

Harvard Harvard University is a private Ivy League research university in Cambridge, Massachusetts. Founded in 1636 as Harvard College and named for its first benefactor, the Puritan clergyman John Harvard, it is the oldest institution of higher le ...

Ph.D students, and in addition they typically supervise about 30 graduate students from other institutions who are pursuing Ph.D. theses at the SAO. About thirty undergraduate students intern at the SAO each year. All together there are about 950 staff (including administrative and management department employees) working at the Center. Black hole - Messier 87 crop max res

Directors

1890–1906 *

1906–1942 * Loyal Blaine Aldrich 1942–1955 *

1955–1973 *

George B. Field George B. Field (born October 25, 1929 in Providence, Rhode Island) is an American astrophysicist. Early life, family and education Field was born in Providence, Rhode Island. His father Winthrop Brooks Field and mother Pauline Woodworth Fie ...

1973–1982 (with the creation of the Harvard-Smithsonian Center for Astrophysics in 1973, the director of SAO and the

became a joint position) *

Irwin I. Shapiro Irwin Ira Shapiro is an American astrophysicist and Timken University Professor at Harvard University. He has been a professor at Harvard since 1982. He was the director of the Center for Astrophysics Harvard & Smithsonian from 1982 to 20 ...

1982–2004 *

Charles R. Alcock Charles Roger Alcock (born 15 June 1951) is a British New Zealander astronomer. He was the director of the Center for Astrophysics Harvard & Smithsonian in Cambridge, Massachusetts from 2004–2022. Career Born in Windsor, Berkshire, England, ...

2004–2022 * Lisa Kewley 2022–

Associates

* Margaret Sordahl

References

External links

*
SAO homepageCenter for Astrophysics , Harvard & Smithsonian
{{Authority control Buildings and structures in Cambridge, Massachusetts Astronomical observatories in Massachusetts Smithsonian Institution research programs Harvard–Smithsonian Center for Astrophysics Research institutes in Massachusetts