Roscoe Frank Sanford (October 6, 1883 – April 7, 1958) was an American

astronomer An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the scope of Earth. They observe astronomical objects such as stars, planets, moons, comets and galaxies – in either o ...

. He was born in

Faribault, Minnesota Faribault ( ) is a city in, and the county seat of, Rice County, Minnesota, United States. The population was 23,352 at the 2010 census. Faribault is approximately south of Minneapolis–Saint Paul. Interstate 35 and Minnesota State Highway ...

, the eldest of five children of Frank W. Sanford and his wife Alberta Nichols. After an early education in his home town he attended the

University of Minnesota The University of Minnesota, formally the University of Minnesota, Twin Cities, (UMN Twin Cities, the U of M, or Minnesota) is a public university, public Land-grant university, land-grant research university in the Minneapolis–Saint Paul, Tw ...

, where he received an

A.B. Bachelor of arts (BA or AB; from the Latin ', ', or ') is a bachelor's degree awarded for an undergraduate program in the arts, or, in some cases, other disciplines. A Bachelor of Arts degree course is generally completed in three or four ye ...

in 1905. He was also a runner up for a

Rhodes scholarship The Rhodes Scholarship is an international postgraduate award for students to study at the University of Oxford, in the United Kingdom. Established in 1902, it is the oldest graduate scholarship in the world. It is considered among the world ...

. He taught

High School A secondary school describes an institution that provides secondary education and also usually includes the building where this takes place. Some secondary schools provide both '' lower secondary education'' (ages 11 to 14) and ''upper seconda ...

students for a year then became an assistant at the Lick Observatory. The Carnegie Institute of Washington approved plans by Lewis Boss for an observation station in

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the souther ...

, and Roscoe Sanford was selected to travel there as an assistant. The nine-man group spent nearly two years making observations of the brightest-magnitude stars in the southern hemisphere, with Roscoe making

telescope A telescope is a device used to observe distant objects by their emission, absorption, or reflection of electromagnetic radiation. Originally meaning only an optical instrument using lenses, curved mirrors, or a combination of both to obse ...

observations and

meridian-circle The meridian circle is an instrument for timing of the passage of stars across the local meridian, an event known as a culmination, while at the same time measuring their angular distance from the nadir. These are special purpose telescopes moun ...

readings. After returning to the United States, he went back to South America in 1911 as an assistant at the Lick southern station in

Santiago, Chile Santiago (, ; ), also known as Santiago de Chile, is the capital and largest city of Chile as well as one of the largest cities in the Americas. It is the center of Chile's most densely populated region, the Santiago Metropolitan Region, whose ...

. There he developed an interest in stellar spectra using photography. Among his work was measurements of velocities of the

Magellanic Clouds The Magellanic Clouds (''Magellanic system'' or ''Nubeculae Magellani'') are two irregular dwarf galaxies in the southern celestial hemisphere. Orbiting the Milky Way galaxy, these satellite galaxies are members of the Local Group. Because bo ...

, the first such study of extra-galactic velocities. He returned to Lick Observatory in 1915, and was granted the Martin Kellogg Fellowship until 1916 then the Lick Fellowship up to 1917. He was awarded his

Ph.D. A Doctor of Philosophy (PhD, Ph.D., or DPhil; Latin: or ') is the most common degree at the highest academic level awarded following a course of study. PhDs are awarded for programs across the whole breadth of academic fields. Because it is a ...

in 1917 from the

University of California The University of California (UC) is a public land-grant research university system in the U.S. state of California. The system is composed of the campuses at Berkeley, Davis, Irvine, Los Angeles, Merced, Riverside, San Diego, San Fran ...

. The same year he was married to Mabel Aline Dyer. The couple would have five children: Jane, Eleanor, Wallace, Allan and Marguerite. Coincidentally, his greatgranddaughter, Kelsey, was born on what would have been his 110th birthday in Michigan. Dr. Sanford spent a short time working at the

Dudley Observatory Dudley Observatory is an astronomical observatory originally located in Albany, New York, and now in Loudonville, New York. It is no longer operating as a scientific observatory, but remains the oldest non-academic institution of astronomical re ...

, then joined the staff of the

Mount Wilson Observatory The Mount Wilson Observatory (MWO) is an astronomical observatory in Los Angeles County, California, United States. The MWO is located on Mount Wilson, a peak in the San Gabriel Mountains near Pasadena, northeast of Los Angeles. The observ ...

. He would remain there for much of the remainder of his career, retiring in 1949. He then spent two years on classified research before returning to Mount Wilson where he continued to contribute until 1956. During his career he published over sixty papers, many of them dealing with the spectra of

spectroscopic binaries A binary star is a system of two stars that are gravitationally bound to and in orbit around each other. Binary stars in the night sky that are seen as a single object to the naked eye are often resolved using a telescope as separate stars, in ...

variable star A variable star is a star whose brightness as seen from Earth (its apparent magnitude) changes with time. This variation may be caused by a change in emitted light or by something partly blocking the light, so variable stars are classified as e ...

s, and

Cepheid variable A Cepheid variable () is a type of star that pulsates radially, varying in both diameter and temperature and producing changes in brightness with a well-defined stable period and amplitude. A strong direct relationship between a Cepheid varia ...

s, including

radial velocity The radial velocity or line-of-sight velocity, also known as radial speed or range rate, of a target with respect to an observer is the rate of change of the distance or range between the two points. It is equivalent to the vector projection ...

measurements. His most significant contribution was to the study of R- and N-class stars belonging to the cool

red dwarf ''Red Dwarf'' is a British science fiction comedy franchise created by Rob Grant and Doug Naylor, which primarily consists of a television sitcom that aired on BBC Two between 1988 and 1999, and on Dave (TV channel), Dave since 2009, gaining a ...

type (later reclassified as

Carbon star A carbon star (C-type star) is typically an asymptotic giant branch star, a luminous red giant, whose atmosphere contains more carbon than oxygen. The two elements combine in the upper layers of the star, forming carbon monoxide, which consumes mo ...

s). He published an atlas of the spectra for late-type Carbon stars, and also determined the spectral features of the isotope

carbon-13 Carbon-13 (13C) is a natural, stable isotope of carbon with a nucleus containing six protons and seven neutrons. As one of the environmental isotopes, it makes up about 1.1% of all natural carbon on Earth. Detection by mass spectrometry A mass ...

. In 1944 he was president of the Astronomical Society of the Pacific, and he served on two of the commissions (29 and 30) of the

International Astronomical Union The International Astronomical Union (IAU; french: link=yes, Union astronomique internationale, UAI) is a nongovernmental organisation with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreach ...

. He was literate in

Spanish Spanish might refer to: * Items from or related to Spain: ** Spaniards are a nation and ethnic group indigenous to Spain **Spanish language, spoken in Spain and many Latin American countries **Spanish cuisine Other places * Spanish, Ontario, Ca ...

and wrote two papers in that language. The crater

Sanford Sanford may refer to: People *Sanford (given name), including a list of people with the name *Sanford (surname), including a list of people with the name Places United States * Sanford, Alabama, a town in Covington County * Sanford, Colorado, ...

on the

Moon The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width ...

is named after him.

References

* R.E. Wilson, 1958,
Roscoe Frank Sanford, 1883-1958
, ''Publications of the Astronomical Society of the Pacific'', Vol. 70, No. 415, p. 360. {{DEFAULTSORT:Sanford, Roscoe Frank 1883 births 1958 deaths University of Minnesota alumni American astronomers