|
Danjon Prismatic Astrolabe (1954), Quito Astronomical Observatory
Danjon may refer to: * André-Louis Danjon André-Louis Danjon (; 6 April 1890 – 21 April 1967) was a French astronomer who served as director of the Observatory of Strasbourg from 1930 to 1945 and of the Paris Observatory from 1945 to 1963. He developed several astronomical instrume ... (1890–1967), French astronomer * Danjon scale, used for measuring lunar eclipse brightness * Danjon (crater), a lunar crater {{Disambiguation, surname ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
André-Louis Danjon
André-Louis Danjon (; 6 April 1890 – 21 April 1967) was a French astronomer who served as director of the Observatory of Strasbourg from 1930 to 1945 and of the Paris Observatory from 1945 to 1963. He developed several astronomical instruments to examine the regularity of the rotation of the earth and among his discoveries was an acceleration of the rotation of the Earth during periods of intense solar activity occurring in 11-year cycles correlated with an increase in earthquakes. The Danjon scale is used for measuring the intensity of lunar eclipses. He noted an increase in the number of dark lunar eclipses with solar activity which is termed as the Danjon effect. Life and work Danjon was born in Caen to drapers Louis Dominique Danjon and Marie Justine Binet. He studied at the Lyce Malherbe and then went to the Ecole Normale Superieure during which time he worked at the observatory of the Societe Astronomique de France. He graduated in 1914 and was conscripted into the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Danjon Scale
The Danjon scale is a five-point scale useful for measuring the appearance and luminosity of the Moon during a total lunar eclipse. It was proposed by André-Louis Danjon in 1921, when postulating that the brightness of a lunar eclipse was related to the solar cycle. An eclipse's rating on the scale is traditionally denoted by the letter ''L''. The scale The Danjon scale is described in the following table: Determining the value of L Determination of the value of L for an eclipse is best done near mid-totality with the naked eye. The scale is subjective, and different observers may determine different values. In addition, different parts of the Moon may have different L values, depending on their distance from the center of the Earth's umbra. Factors affecting the value of L Many factors can affect the appearance of the Moon during a lunar eclipse. The Moon's path through the Earth's umbra is important, but so too are the current conditions of the Earth's atmosphere. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |