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 .
5-548: L-value , L value or lvalue may refer to: In astronomy, a measure of brightness of a lunar eclipse on the Danjon scale L-value (computer science) , denoting an object to which values can be assigned In number theory, the value of an L-function In space physics, the value assigned to an L-shell , a particular set of planetary magnetic field lines See also [ edit ] R-value (disambiguation) Topics referred to by
10-408: A red hue. The amount of light refracted affects the brightness of the moon at mid-eclipse, and this depends on several factors. Volcanic eruptions are one of the most significant - eruptions which spew significant amounts of volcanic ash into the air are generally followed by several years of dark, deep red eclipses. The effect of the 1991 eruption of Mount Pinatubo on subsequent lunar eclipses
15-510: Is different from Wikidata All article disambiguation pages All disambiguation pages Danjon scale The Danjon scale is described in the following table: 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
20-500: The center of the Earth's umbra . 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 . While the Earth's shadow blocks any direct light from striking the Moon during a lunar eclipse, some light is refracted through the Earth's atmosphere giving the Moon
25-410: The same term [REDACTED] This disambiguation page lists articles associated with the title L-value . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=L-value&oldid=983441315 " Category : Disambiguation pages Hidden categories: Short description
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