Difference between revisions of "Magnitude"
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[[Magnitude]] is a unit of measure for the brightness (or visibility) of stellar object. There are two kinds of magnitude, '''Apparent Magnitude''' (''m'') which measures the brightness of a stellar object from the point of view of the observer. '''Absolute Magnitude''' (''M'') measures the brightness of a stellar object from 10 [[parsec]]s, or a planetary object from 1 [[Astronomical unit]]. | [[Magnitude]] is a unit of measure for the brightness (or visibility) of stellar object. There are two kinds of magnitude, '''Apparent Magnitude''' (''m'') which measures the brightness of a stellar object from the point of view of the observer. '''Absolute Magnitude''' (''M'') measures the brightness of a stellar object from 10 [[parsec]]s, or a planetary object from 1 [[Astronomical unit]]. | ||
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Absolute magnitudes for stars generally range from -10 to +17. | Absolute magnitudes for stars generally range from -10 to +17. | ||
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* Faintest objects visible with binoculars: 9.5 | * Faintest objects visible with binoculars: 9.5 | ||
| − | == Conversion == | + | |
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| + | [[File: Imperial Sunburst-Sun-IISS-Traveller.gif|right]] | ||
| + | No information or synopsis yet available. | ||
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| + | == Description ([[Specifications]]) == | ||
| + | No information yet available. | ||
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| + | === Conversion === | ||
Given the absolute magnitude <math>M\!\,</math>, for objects within our galaxy you can also calculate the apparent magnitude <math>m\!\,</math> from any distance <math>D_L\!\,</math>: | Given the absolute magnitude <math>M\!\,</math>, for objects within our galaxy you can also calculate the apparent magnitude <math>m\!\,</math> from any distance <math>D_L\!\,</math>: | ||
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where <math>D_L\!\,</math> is the star's luminosity distance in [[parsec]]s, which are (≈ 3.2616 [[light-year]]s) | where <math>D_L\!\,</math> is the star's luminosity distance in [[parsec]]s, which are (≈ 3.2616 [[light-year]]s) | ||
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== History & Background ([[Dossier]]) == | == History & Background ([[Dossier]]) == | ||
| − | + | The original magnitude measurement was a scale of 1 to 6 to categorize the stars visible in the [[Terra (world)|Terran]] skies. This was later formalized into a logarithmic scale, with the smaller numbers indicating brighter objects than larger ones. The scale is defined such that each 5 points magnitude is 100 times brighter (or dimmer). The scale also extends into the negative numbers, so for example magnitude -5 is 100 times brighter than magnitude 0. | |
== References & Contributors (Sources) == | == References & Contributors (Sources) == | ||
| + | {{Wikipedia|Apparent_magnitude}} | ||
| + | {{Wikipedia|Absolute_magnitude}} | ||
{{Intermediate}} | {{Intermediate}} | ||
{{Detail}} | {{Detail}} | ||
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| − | {{LEN|}} | + | {{LEN|Star}} |
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{{LE|Metric|Unit of measurement}} | {{LE|Metric|Unit of measurement}} | ||
Revision as of 18:03, 23 January 2019
Magnitude is a unit of measure for the brightness (or visibility) of stellar object. There are two kinds of magnitude, Apparent Magnitude (m) which measures the brightness of a stellar object from the point of view of the observer. Absolute Magnitude (M) measures the brightness of a stellar object from 10 parsecs, or a planetary object from 1 Astronomical unit.
Absolute magnitudes for stars generally range from -10 to +17.
Some points of reference:
- Sol from Terra: -26.73
- Projects enough light to cast shadows: -5
- Faintest objects observable during the day with naked eye: −3.9
- Faintest stars visible in an urban neighborhood with naked eye: 3
- Faintest stars observable with naked eye under perfect conditions: 6.5
- Faintest objects visible with binoculars: 9.5
No information or synopsis yet available.
Description (Specifications)
No information yet available.
Conversion
Given the absolute magnitude <math>M\!\,</math>, for objects within our galaxy you can also calculate the apparent magnitude <math>m\!\,</math> from any distance <math>D_L\!\,</math>:
- <math> m = M + 5 (\log_{10}{D_L} - 1)\!\,</math>
One can compute the absolute magnitude <math>M\!\,</math> of an object given its apparent magnitude <math>m\!\,</math> and luminosity distance <math>D_L\!\,</math>:
- <math> M = m - 5 ((\log_{10}{D_L}) - 1)\!\,</math>
where <math>D_L\!\,</math> is the star's luminosity distance in parsecs, which are (≈ 3.2616 light-years)
History & Background (Dossier)
The original magnitude measurement was a scale of 1 to 6 to categorize the stars visible in the Terran skies. This was later formalized into a logarithmic scale, with the smaller numbers indicating brighter objects than larger ones. The scale is defined such that each 5 points magnitude is 100 times brighter (or dimmer). The scale also extends into the negative numbers, so for example magnitude -5 is 100 times brighter than magnitude 0.
References & Contributors (Sources)
| This page uses content from Wikipedia. The original article was at Apparent_magnitude. The list of authors can be seen in the page history. The text of Wikipedia is available under the Commons Attribution-ShareAlike 3.0 Unported License. |
| This page uses content from Wikipedia. The original article was at Absolute_magnitude. The list of authors can be seen in the page history. The text of Wikipedia is available under the Commons Attribution-ShareAlike 3.0 Unported License. |
| This article is missing content for one or more detailed sections. Additional details are required to complete the article. You can help the Traveller Wiki by expanding it. |
- TBD
- Traveller Wiki Editorial Team
- Author & Contributor: Lord (Marquis) and Master of Sophontology Maksim-Smelchak of the Ministry of Science
