Ferdinand Ellerman | |
|---|---|
 Ferdinand Ellerman, c. 1920 | |
| Born | May 13, 1869 |
| Died | March 20, 1940 (aged 70) |
| Spouse | Hermine Louise Hoenny [2] |
| Children | Louise [2] |
| Parents | |
Ferdinand Ellerman (May 13, 1869 to March 20, 1940) was an American astronomer and photographer. He spent a good part of his career as an associate of the solar astronomer George E. Hale, and is known for his study of a phenomenon in the solar chromosphere later dubbed Ellerman bombs.
He was born in Centralia, Illinois on May 13, 1869, the son of Mathias Ellerman and Rosa A. née Fleischbein. Ferdinand attended High School in Belleville, Illinois, [2] then moved to Chicago and was employed at the James S. Kirk Company, [3] a soap manufacturing business. [4] [5] During his work, he acquired skill in the use of machine tools and photography. [3]
Ellerman was hired as an assistant by astronomer George E. Hale in 1892 to observe at his private Kenwood Observatory in Chicago, beginning a working relationship that would last until Hale's death in 1938. [6] The two likely first met during the initial meeting for the Chicago Section of the Astronomical Society of the Pacific, in November 1890, and Ellerman may have first worked as a volunteer for Hale. [7] Ellerman performed much of the observation work for Hale, who focused on travel and organizational activities. [8] : 10–11 On May 16, 1895, Ellerman was married to Hermine Louise Hoenny. They would have one daughter, Louise, who was born July 29, 1901. [2]
When Hale started Yerkes Observatory in Wisconsin, he brought along Ellerman in 1895. [3] [9] There, Ellerman got along well with the local people and in 1899 was elected clerk of the local county school district. [8] : 28 Much of Ellerman's observation time was spent with the Rumford spectroheliograph, [10] as well as photographing the stellar spectra of Secchi's Fourth Type, [11] [3] later termed carbon stars. In 1900, Ellerman joined the AAS solar eclipse expedition to Wadesboro, North Carolina. [12]
During March 1904, Ellerman joined Hale on an expedition to investigate the viewing conditions on Mount Wilson in California. The goal was to determine the suitability for a proposed observatory at the site that was to be financed by the Carnegie Institution. The initial planned instrument was to be the Snow Horizontal Telescope, a solar telescope funded by Helen Snow of Chicago. [13] This instrument was made operational on March 15, 1905, with Ellerman serving as the primary observer on the new spectroheliograph. [14] [15] During the early period, Ellerman took a photograph of the Sun in white light nearly every day, then images at a specific wavelength. [7] His skills at repair and jury-rigging equipment proved invaluable at the remote mountain site. A fully-equipped machine shop was soon added to the Observatory for Ellerman's use. Much of the subsequent growth of the Mount Wilson Observatory was documented by Ellerman's photography. [16]
Ellerman's work with Hale resulted in the discovery of solar vortices, which in turn led to the identification of the magnetic fields of Sun spots in 1908. Later work discerned the polarity of Sun spots, which led to the discovery of the reversal of the magnetic field in these features. [3] [17] In 1910, Ellerman was granted a leave from the Carnegie Institution to undergo a one-man expedition to the Hawaiian Islands for the observation of Halley's Comet during its passage. [18] Arriving on March 28, his observation station was set up on Diamond Head, Hawaii. He first sighted the comet on April 14, and by the 25th he was able to take observations. Despite clouds and windy conditions, he took a total of 73 photographs of the comet on 36 different dates. [19] [20]
While at the Mount Wilson Solar Observatory in 1915, Ellerman studied an unusual phenomenon observed at multiple locations in the lower chromosphere layer of the Sun. These events showed bright emission features in the wings of hydrogen-alpha absorption lines. [21] The phenomenon later became referred to as Ellerman bombs, as he observed they were localized and generally only lasted 10–20 minutes. [22] Although Ellerman studied this phenomenon, the original discovery of this behavior was made by W. M. Mitchell in 1900, near an active region of the Sun. [23]
Ellerman received an honorary MS degree from Occidental College on June 20, 1927. [24] During the spring of 1929, Ellerman accompanied E. Hubble and M. L. Humason in a series of trips to find a suitable location for the proposed Hale Telescope. These journeys were made to a hilly region to the south of Los Angeles and to Arizona, with the goal of checking the viewing conditions. Ellerman served as the mechanic for the trip, setting up the small telescopes. [25] His reports would heavily influence the selection of the final site for the telescope. [16]
Ellerman retired in 1938. [3] During a bout of influenza, he died of pneumonia on March 20, 1940, at the Queen of Angels Hospital in Los Angeles, California. [1] Ellerman was considered a friendly, jolly, talkative man. [8] : 28 He was an outdoorsman who was interested in sports, participated in the local community, and lectured in popular astronomy. [3]
The 46.21 km (28.71 mi) diameter Ellerman crater on the far side of the Moon was named after him by the IAU in 1970. [26]
The Astrophysical Journal (ApJ) is a peer-reviewed scientific journal of astrophysics and astronomy, established in 1895 by American astronomers George Ellery Hale and James Edward Keeler. The journal discontinued its print edition and became an electronic-only journal in 2015.
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. Ownership was transferred to the non-profit Yerkes Future Foundation (YFF) in May 2020, which began restoration and renovation of the historic building and grounds. Re-opening for public tours and programming began May 27, 2022.
The Mount Wilson Observatory (MWO) is an astronomical observatory in Los Angeles County, California, United States. The MWO is located on Mount Wilson, a 5,710-foot (1,740-meter) peak in the San Gabriel Mountains near Pasadena, northeast of Los Angeles.
Palomar Observatory is an astronomical research observatory in San Diego County, California, United States, in the Palomar Mountain Range. It is owned and operated by the California Institute of Technology (Caltech). Research time at the observatory is granted to Caltech and its research partners, which include the Jet Propulsion Laboratory (JPL), Yale University, and the National Astronomical Observatories of China.
Charles Dillon Perrine was an American astronomer at the Lick Observatory in California (1893-1909) who moved to Cordoba, Argentina to accept the position of Director of the Argentine National Observatory (1909-1936). The Cordoba Observatory under Perrine's direction made the first attempts to prove Einstein's theory of relativity by astronomical observation of the deflection of starlight near the Sun during the solar eclipse of October 10, 1912 in Cristina (Brazil), and the solar eclipse of August 21, 1914 at Feodosia, Crimea, Russian Empire. Rain in 1912 and clouds in 1914 prevented results.
George A. Van Biesbroeck was a Belgian–American astronomer. He worked at observatories in Belgium, Germany and the United States. He specialized in the observation of double stars, asteroids and comets. He is notable for his long career as an observational astronomer.
George Ellery Hale was an American astrophysicist, best known for his discovery of magnetic fields in sunspots, and as the leader or key figure in the planning or construction of several world-leading telescopes; namely, the 40-inch refracting telescope at Yerkes Observatory, 60-inch Hale reflecting telescope at Mount Wilson Observatory, 100-inch Hooker reflecting telescope at Mount Wilson, and the 200-inch Hale reflecting telescope at Palomar Observatory. He played a key role in the foundation of the International Union for Cooperation in Solar Research and the National Research Council, and in developing the California Institute of Technology into a leading research university.
Milton La Salle Humason was an American astronomer. He worked with Edwin Hubble to measure the redshift of nebulas in the early 20th century, providing evidence of the expansion of the universe.
The Hale Telescope is a 200-inch (5.1 m), f/3.3 reflecting telescope at the Palomar Observatory in San Diego County, California, US, named after astronomer George Ellery Hale. With funding from the Rockefeller Foundation in 1928, he orchestrated the planning, design, and construction of the observatory, but with the project ending up taking 20 years he did not live to see its commissioning. The Hale was groundbreaking for its time, with double the diameter of the second-largest telescope, and pioneered many new technologies in telescope mount design and in the design and fabrication of its large aluminum coated "honeycomb" low thermal expansion Pyrex mirror. It was completed in 1949 and is still in active use.
1024 Hale, provisional designation A923 YO13, is a carbonaceous background asteroid from the outer regions of the asteroid belt, approximately 45 kilometers (28 miles) in diameter. The asteroid was discovered on 2 December 1923, by Belgian–American astronomer George Van Biesbroeck at the Yerkes Observatory in Wisconsin, United States. It was named for American astronomer George Ellery Hale. The dark C-type asteroid may have a rotation period of 16 hours.
The Crossley telescope is a 36-inch (910 mm) reflecting telescope located at Lick Observatory in the U.S. state of California. It was used between 1895 and 2010, and was donated to the observatory by Edward Crossley, its namesake.
The Kenwood Astrophysical Observatory was the personal observatory of George Ellery Hale, constructed by his father, William E. Hale, in 1890 at the family home in the Kenwood section of Chicago. It was here that the spectroheliograph, which Hale had invented while attending MIT, was first put to practical use; and it was here that Hale established the Astrophysical Journal. Kenwood's principal instrument was a twelve-inch refractor, which was used in conjunction with a Rowland grating as part of the spectroheliograph. Hale hired Ferdinand Ellerman as an assistant; years later, the two would work together again at the Mount Wilson Observatory.
Nicholas Ulrich Mayall was an American observational astronomer. After obtaining his doctorate from the University of California, Berkeley, Mayall worked at the Lick Observatory, where he remained from 1934 to 1960, except for a brief period at MIT's Radiation Laboratory during World War II.
William Pendry Bidelman was an American astronomer. Born in Los Angeles, and raised in North Dakota, he was noted for classifying the spectra of stars, and considered a pioneer in recognizing and classifying sub-groups of the peculiar stars.
Hannah Steele Pettit, also known as Hannah Bard Steele Pettit, was an American astronomer who spent a notable amount of her career working as an assistant at the Yerkes Observatory, where she and her husband Edison Pettit jointly published photographs on the corona of a solar eclipse.
Alice Hall Farnsworth was an American astronomer. She was director of John Payson Williston Observatory at Mount Holyoke College from 1936 until her retirement in 1957.
Meudon Great Refractor is a double telescope with lenses, in Meudon, France. It is a twin refracting telescope built in 1891, with one visual and one photographic, on a single square-tube together on an equatorial mount, inside a dome. The Refractor was built for the Meudon Observatory, and is the largest double doublet refracting telescope in Europe, but about the same size as several telescopes in this period, when this style of telescope was popular. Other large telescopes of a similar type include the James Lick telescope (91.4), Potsdam Great Refractor (80+50 cm), and the Greenwich 28 inch refractor (71.1 cm).
Myrtle Leila Richmond was an American astronomical researcher, a computer who worked at the Mount Wilson Observatory from 1913 to 1947.
The Observatorio Manuel Foster, or Manuel Foster Observatory, is an astronomical observatory constructed on Cerro San Cristóbal near Santiago, Chile in 1903. This site was originally known as the D. O. Mills Observatory after the philanthropist Darius Ogden Mills. It was built as an offshoot of the Lick Observatory to observe stars in the southern hemisphere, and, under the direction of the American astronomer W. W. Campbell, was used in an extensive project to determine the apex of the Sun's motion through space.
The Snow Solar Telescope is a solar telescope at the Mount Wilson Observatory in California. It was originally named the Snow Horizontal Telescope as it uses a coelostat to deflect light from the Sun into a fixed horizontal shed where it can be studied. The telescope was funded by a donation from Helen E. Snow of Chicago in 1903. It was assembled at Yerkes Observatory then transferred to Mt. Wilson in 1905.
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