Bonnard John Teegarden (born August 23, 1940) is an American astrophysicist formerly with

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, succeedi ...

Goddard Space Flight Center The Goddard Space Flight Center (GSFC) is a major NASA space research laboratory located approximately northeast of Washington, D.C. in Greenbelt, Maryland, United States. Established on May 1, 1959 as NASA's first space flight center, GSFC emp ...

, now retired. He spent most of his career studying cosmic

gamma ray 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 nucleus, atomic nuclei. It consists of the shortest wavelength electromagnetic wav ...

s and is best known to the public for leading the team that discovered Teegarden's star in 2003.

Education

Teegarden grew up in

Fair Haven, New Jersey Fair Haven is a borough in Monmouth County, in the U.S. state of New Jersey, and part of the New York Metropolitan Area. Fair Haven is located on the Rumson peninsula along the Navesink River and is bordered by Red Bank and Little Silver to t ...

and graduated from

Rumson-Fair Haven Regional High School The Rumson-Fair Haven Regional High School (often abbreviated RFH) is a regional, four-year comprehensive public high school and school district in the eastern United States, serving students in ninth through twelfth grades from the suburba ...

in Rumson in 1958. He earned a Bachelor of Science from the

Massachusetts Institute of Technology The Massachusetts Institute of Technology (MIT) is a Private university, private Land-grant university, land-grant research university in Cambridge, Massachusetts. Established in 1861, MIT has played a key role in the development of modern t ...

in 1962 and a Doctor of Philosophy from the

University of Maryland The University of Maryland, College Park (University of Maryland, UMD, or simply Maryland) is a public university, public Land-grant university, land-grant research university in College Park, Maryland. Founded in 1856, UMD is the Flagship un ...

in 1967. His thesis was "A Study of Low Energy Galactic Cosmic Rays" and his advisor was

Frank B. McDonald Frank Bethune McDonald (May 28, 1925 – August 31, 2012) was an American astrophysicist who helped design scientific instruments for research flights into space. He was a key force behind several initiatives and programs of the National Aeronau ...

Career

The discovery of Teegarden's star

The discovery of Teegarden's star came as somewhat of a surprise as no close-by stars had been discovered for many decades. Teegarden's team found this star in data taken years earlier by an unrelated program searching for

near-Earth asteroids A near-Earth object (NEO) is any small Solar System body whose orbit brings it into proximity with Earth. By convention, a Solar System body is a NEO if its closest approach to the Sun (perihelion) is less than 1.3 astronomical units (AU). ...

. The real excitement was from the initial measurements the team made for the

parallax Parallax is a displacement or difference in the apparent position of an object viewed along two different lines of sight and is measured by the angle or semi-angle of inclination between those two lines. Due to foreshortening, nearby object ...

of this star. These initial measurements indicated that the star may be very close at a distance of about seven

light-year A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 101 ...

s. This would have made it the third-closest

star system A star system or stellar system is a small number of stars that orbit each other, bound by gravitational attraction. A large group of stars bound by gravitation is generally called a '' star cluster'' or ''galaxy'', although, broadly speakin ...

. This excitement resulted in numerous popular press articles and public interest. In the years since the discovery was announced the measured distances gradually increased. The accepted distance is now more than twelve light-years and public interest has faded somewhat, but not before Teegarden was rewarded with the name of this newly discovered star, although other designations are sometimes used as well.

Other work

Teegarden was a

cosmic ray Cosmic rays are high-energy particles or clusters of particles (primarily represented by protons or atomic nuclei) that move through space at nearly the speed of light. They originate from the Sun, from outside of the Solar System in our ow ...

researcher at NASA's

for all of his professional life. He was co-investigator on the Pioneer Jupiter cosmic ray experiments and later an investigator on the space based

INTEGRAL In mathematics, an integral assigns numbers to functions in a way that describes displacement, area, volume, and other concepts that arise by combining infinitesimal data. The process of finding integrals is called integration. Along with ...

and

BATSE The Compton Gamma Ray Observatory (CGRO) was a space observatory detecting photons with photon energy, energies from 20 kElectronvolt#Properties, eV to 30 GeV, in Earth orbit from 1991 to 2000. The observatory featured four main tele ...

experiments. He was also involved in studies of stellar

nucleosynthesis Nucleosynthesis is the process that creates new atomic nuclei from pre-existing nucleons (protons and neutrons) and nuclei. According to current theories, the first nuclei were formed a few minutes after the Big Bang, through nuclear reactions in ...

. He is a prolific researcher with 200 articles listed in SAO/

NASA Astrophysics Data System The SAO/NASA Astrophysics Data System (ADS) is an online database of over 16 million astronomy and physics papers from both peer reviewed and non-peer reviewed sources. Abstracts are available free online for almost all articles, and full scanned a ...

Personal life

After retiring from NASA Teegarden and his wife moved to

Annapolis Annapolis ( ) is the capital city of the U.S. state of Maryland and the county seat of, and only incorporated city in, Anne Arundel County. Situated on the Chesapeake Bay at the mouth of the Severn River, south of Baltimore and about east ...

, Maryland. He now works wood, and sails. He has developed special software for making decorative wooden bowls.

References

External links

Teegarden Turnings
{{DEFAULTSORT:Teegarden, Bonnard John Place of birth missing (living people) 21st-century American physicists American astrophysicists NASA astrophysicists Cosmic ray physicists Living people Massachusetts Institute of Technology alumni People from Annapolis, Maryland People from Fair Haven, New Jersey University of Maryland, College Park alumni Rumson-Fair Haven Regional High School alumni 1940 births