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Ernest Leonard Johnson
Ernest Leonard Johnson (1891–1977) was a South African astronomer and a former staff member of the Union Observatory in Johannesburg, South Africa. He is known for the discovery of 18 asteroids between 1946–1951, as well as several comets. On 25 August 1949, he discovered 48P/Johnson, a periodic comet expected to pass no closer than 1.2 to 1.3 AU from our planet in 2025. Johnson received the "Donohoe Comet Medal" twice before retiring in 1956. He died in 1977. Biography Johnson was the son of William Johnson, a medical practitioner, and Rachel Sarah Joan Sanderson. He matriculated at Grey College, Bloemfontein, South Africa and started working on a mine but when his brother, Cecil Robert Johnson, was killed in a mining accident he applied for a position at the Union Observatory in Johannesburg, South Africa. He started work there as a learner astronomer in 1914. He served in the armed forces of the Union of South Africa in World War I (1914-1918) during the campaign in Ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bloemfontein
Bloemfontein, ( ; , "fountain of flowers") also known as Bloem, is one of South Africa's three capital cities and the capital of the Free State (province), Free State province. It serves as the country's judicial capital, along with legislative capital Cape Town and Administration (government), administrative capital Pretoria. Bloemfontein is the seventh-largest city in South Africa. Situated at an elevation of above sea level, the city is home to approximately 520,000 residents and forms part of the Mangaung Metropolitan Municipality which has a population of 747,431. It was one of the host cities for the 2010 FIFA World Cup. The city of Bloemfontein hosts the Supreme Court of Appeal (South Africa), Supreme Court of Appeal of South Africa, the Franklin Game Reserve, :af:Naval Hill, Naval Hill, the Maselspoort, Maselspoort Resort and the :af:Sand du Plessis-teaterkompleks, Sand du Plessis Theatre. The city hosts numerous museums, including the National Women's Monument, th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Royal Flying Corps
"Through Adversity to the Stars" , colors = , colours_label = , march = , mascot = , anniversaries = , decorations = , battle_honours = , battles_label = Wars , battles = First World War , disbanded = merged with RNAS to become Royal Air Force (RAF), 1918 , current_commander = , current_commander_label = , ceremonial_chief = , ceremonial_chief_label = , colonel_of_the_regiment = , colonel_of_the_regiment_label = , notable_commanders = Sir David HendersonHugh Trenchard , identification_symbol = , identification_symbol_label = Roundel , identification_symbol_2 = , identification_symbol_2_label = Flag , aircraft_attack = , aircraft_bomber = , aircraft_el ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1609 Brenda
1609 Brenda, provisional designation , is a stony asteroid from the central region of the asteroid belt, approximately 28 kilometers in diameter. It was discovered on 10 July 1951, by South African astronomer Ernest Johnson at the Johannesburg Observatory in South Africa, and named after his granddaughter, Brenda. Orbit and classification The S-type asteroid orbits the Sun in the central main-belt at a distance of 1.9–3.2 AU once every 4 years and 2 months (1,518 days). Its orbit has an eccentricity of 0.25 and an inclination of 19 ° with respect to the ecliptic. ''Brenda'' was first identified as at Simeiz Observatory in 1925. Its observation arc begins 17 years prior to its official discovery observation, with its identification , also made at Simeiz. Physical characteristics American astronomer Richard Binzel obtained the first rotational lightcurve of ''Brenda'' in June 1984. It gave a rotation period of 19.46 hours with a brightness variation of 0.16 magnitu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1607 Mavis
1607 Mavis, provisional designation , is a stony asteroid from the central region of the asteroid belt, approximately 12 kilometers in diameter. It was discovered on 3 September 1950, by South African astronomer Ernest Johnson at Johannesburg Observatory in South Africa. It was later named after the wife of astronomer Jacobus Bruwer. Orbit and classification This asteroid orbits the Sun in the middle main-belt at a distance of 1.8–3.3 AU once every 4 years and 1 month (1,487 days). Its orbit has an eccentricity of 0.30 and an inclination of 9 ° with respect to the ecliptic. The asteroid's observation arc begins with its official discovery observations, as the two previous identifications, and , made at Heidelberg and Simeiz in 1903 and 1934, respectively, remained unused. Physical characteristics ''Mavis'' is a stony S-type asteroid. Rotation period In September 2007, Australian astronomers Collin Bembrick and Julian Oey independently obtained two rotationa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1585 Union
1585 Union, provisional designation , is a dark background asteroid from the outer regions of the asteroid belt, approximately 52 kilometers in diameter. It was discovered on 7 September 1947, by South African astronomer Ernest Johnson at the Union Observatory in Johannesburg, South Africa. The asteroid was named after the discovering observatory. Orbit and classification ''Union'' is not a member of any known asteroid family. It orbits the Sun in the outer main belt at a distance of 2.0–3.8 AU once every 5.01 years (1,830 days). Its orbit has an eccentricity of 0.31 and an inclination of 26 ° with respect to the ecliptic. In 1929, the asteroid was first identified as at the Uccle Observatory in Belgium. The body's observation arc begins at the Finnish Turku Observatory in February 1939, more than 17 years prior to its official discovery observation at Johannesburg. Physical characteristics ''Union'' has been characterized as a P-type asteroid by the Wide-fiel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1568 Aisleen
1568 Aisleen, provisional designation , is a stony Phocaea asteroid from the inner regions of the asteroid belt, approximately 12.5 kilometers in diameter. It was discovered on 21 August 1946, by South African astronomer Ernest Johnson at Johannesburg Observatory in South Africa. It is named for the discoverer's wife, Aisleen Johnson. Orbit and classification The S-type asteroid is a member of the Phocaea family (), a group of asteroids with similar orbital characteristics. It orbits the Sun at a distance of 1.8–3.0 AU once every 3 years and 7 months (1,318 days). Its orbit has an eccentricity of 0.25 and an inclination of 25 ° with respect to the ecliptic. As no precoveries were taken, and no prior identifications were made, ''Aisleen''s observation arc begins with its official discovery observation at Johannesburg. Physical characteristics Rotation and pole In August 2000, a rotational lightcurve of ''Aisleen'' was obtained from photometric observations made b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Minor Planet Center
The Minor Planet Center (MPC) is the official body for observing and reporting on minor planets under the auspices of the International Astronomical Union (IAU). Founded in 1947, it operates at the Smithsonian Astrophysical Observatory. Function The Minor Planet Center is the official worldwide organization in charge of collecting observational data for minor planets (such as asteroids), calculating their orbits and publishing this information via the '' Minor Planet Circulars''. Under the auspices of the International Astronomical Union (IAU), it operates at the Smithsonian Astrophysical Observatory, which is part of the Center for Astrophysics along with the Harvard College Observatory. The MPC runs a number of free online services for observers to assist them in observing minor planets and comets. The complete catalogue of minor planet orbits (sometimes referred to as the "Minor Planet Catalogue") may also be freely downloaded. In addition to astrometric data, the MPC collect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomical Society Of Southern Africa
The Astronomical Society of Southern Africa (ASSA), formed in 1922, is a widespread body consisting of both amateur and professional astronomers. There are eight autonomous centres throughout Southern Africa. History The Cape Astronomical Association was established in 1912, shortly after the 1910 appearance of Halley's Comet. Sydney Samuel Hough, HM Astronomer at the Cape, was chosen President. In 1918, the Johannesburg Astronomical Association was created, with RTA Innes, Union Astronomer, as President. In 1922 it was decided to merge the two Associations to form the Astronomical Society of South Africa after an invitation from the Cape Association. In 1956 the name was amended to become the Astronomical Society of Southern Africa. Membership and publications Membership is open to all interested persons. The Society publishes the on-line peer-reviewed journal ''Monthly Notes of the Astronomical Society of Southern Africa'' (''MNASSA''). In addition to ''MNASSA'', the annual ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Great Comet
A great comet is a comet that becomes exceptionally bright. There is no official definition; often the term is attached to comets such as Halley's Comet, which during certain appearances are bright enough to be noticed by casual observers who are not looking for them, and become well known outside the astronomical community. Great comets appear at irregular, unpredictable intervals, on average about once per decade. Although comets are officially named after their discoverers, great comets are sometimes also referred to by the year in which they appeared great, using the formulation "The Great Comet of ...", followed by the year. Causes The vast majority of comets are never bright enough to be seen by the naked eye, and generally pass through the inner Solar System unseen by anyone except astronomers. However, occasionally a comet may brighten to naked eye visibility, and even more rarely it may become as bright as or brighter than the brightest stars. The requirements for thi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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