Frank Elmore Ross (April 2, 1874 – September 21, 1960) 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 ...

and

physicist A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe. Physicists generally are interested in the root or ultimate cau ...

. He was born in

San Francisco, California San Francisco (; Spanish for " Saint Francis"), officially the City and County of San Francisco, is the commercial, financial, and cultural center of Northern California. The city proper is the fourth most populous in California and 17th ...

and died in

Altadena, California Altadena () ("Alta", Spanish language, Spanish for "Upper", and "dena" from Pasadena, California, Pasadena) is an unincorporated area and census-designated place in the Verdugo Mountains region of Los Angeles County, California, approximately 14 ...

. In 1901 he received his doctorate 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 Franci ...

. In 1905 he became director of the

International Latitude Observatory __NOTOC__ The International Latitude Service was created by the International Geodetic Association in 1899 to study variations in latitude caused by polar motion, precession, or "wobble" of the Earth's axis. The original ''International Latitu ...

station at

Gaithersburg, Maryland Gaithersburg ( ), officially the City of Gaithersburg, is a city in Montgomery County, Maryland, United States. At the time of the 2020 U.S. Census, Gaithersburg had a population of 69,657, making it the ninth-largest location in the state. Gai ...

. In 1915 he became a physicist for

Eastman Kodak Company The Eastman Kodak Company (referred to simply as Kodak ) is an American public company that produces various products related to its historic basis in analogue photography. The company is headquartered in Rochester, New York, and is incorpor ...

Rochester, New York Rochester () is a city in the U.S. state of New York, the seat of Monroe County, and the fourth-most populous in the state after New York City, Buffalo, and Yonkers, with a population of 211,328 at the 2020 United States census. Located in W ...

. He accepted a position at

Yerkes Observatory Yerkes Observatory ( ) is an astronomical observatory located in Williams Bay, Wisconsin, United States. The observatory was operated by the University of Chicago Department of Astronomy and Astrophysics from its founding in 1897 to 2018. Owner ...

in 1924 and worked there until his retirement in 1939. His first important work was the calculation of the first reliable orbit of Saturn's moon Phoebe in 1905, and he also calculated orbits for

Jupiter Jupiter is the fifth planet from the Sun and the largest in the Solar System. It is a gas giant with a mass more than two and a half times that of all the other planets in the Solar System combined, but slightly less than one-thousandth t ...

satellite A satellite or artificial satellite is an object intentionally placed into orbit in outer space. Except for passive satellites, most satellites have an electricity generation system for equipment on board, such as solar panels or radioi ...

s Himalia and Elara. When working for Eastman Kodak he investigated photographic emulsions and the design of wide-angle lenses for astronomical use. At

he was the successor to the late E. E. Barnard, inheriting Barnard's collection of photographic plates. Ross decided to repeat the same series of images and compare the results with a

blink comparator A blink comparator is a viewing apparatus formerly used by astronomers to find differences between two photographs of the night sky. It permits rapid switching from viewing one photograph to viewing the other, "blinking" back and forth between th ...

. In doing so, he discovered 379 new variable stars and over 1000 stars of high proper motion. Some of the high–proper motion stars turned out to be quite nearby, and many of these stars (such as Ross 154) are still widely known by the catalog number he gave them. During the opposition of

Mars Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury. In the English language, Mars is named for the Roman god of war. Mars is a terrestrial planet with a thin at ...

in 1926 he photographed the planet in different colors, using the Mount Wilson 60-inch

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 observ ...

. The following year he obtained

ultraviolet Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nm (with a corresponding frequency around 30 PHz) to 400 nm (750 THz), shorter than that of visible light, but longer than X-rays. UV radiation ...

pictures of

Venus Venus is the second planet from the Sun. It is sometimes called Earth's "sister" or "twin" planet as it is almost as large and has a similar composition. As an interior planet to Earth, Venus (like Mercury) appears in Earth's sky never f ...

, which showed structure in its cloud cover for the first time. In 1935, he published an article describing the design of a two-lens system to correct for the coma aberration of parabolic mirrors, including those at the 60-inch and 100-inch telescopes at Mount Wilson Observatory. Such a corrector is since known as the Ross corrector. The crater Ross on

is named after him, and the crater Ross 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 of ...

is jointly named after him and

James Clark Ross Sir James Clark Ross (15 April 1800 – 3 April 1862) was a British Royal Navy officer and polar explorer known for his explorations of the Arctic, participating in two expeditions led by his uncle John Ross, and four led by William Edwa ...

. He was awarded the

Franklin Institute The Franklin Institute is a science museum and the center of science education and research in Philadelphia, Pennsylvania. It is named after the American scientist and statesman Benjamin Franklin. It houses the Benjamin Franklin National Memori ...

John Price Wetherill Medal The John Price Wetherill Medal was an award of the Franklin Institute. It was established with a bequest given by the family of John Price Wetherill (1844–1906) on April 3, 1917. On June 10, 1925, the Board of Managers voted to create a silver ...

in 1928.

References

External links

Obs 81 (1961) 76
(one sentence)

National Academy of Sciences Biographical Memoir (1967)

JHA 38 (2007)
(biography by D.E. Osterbrock) 1874 births 1960 deaths People from San Francisco American physicists American astronomers * Scientists from California Members of the United States National Academy of Sciences {{US-astronomer-stub