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Search: id:A053406
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| A053406 |
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Number of stars brighter than visual magnitude n-1. |
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+0
2
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| 1, 4, 15, 49, 172, 511, 1600, 4968, 15328, 40858, 82484, 106963, 114376, 116592, 117100, 117127, 117128, 117129
(list; graph; listen)
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OFFSET
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0,2
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COMMENT
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These numbers are not well-defined and the sequence is included only for completeness.
The visual magnitude (m) scale is logarithmic : for two stars of brightness i1 and i2 (as seen from the Earth), the magnitude difference m1 - m2 = - log(i1/i2)*100^(1/5). Fainter stars have a higher magnitude number. Data collected by the Hipparcos satellite and exhaustive up to about 9 mag (n=10). At fainter magnitudes (n > 10), the data are increasingly fragmentary (thus the slowing rate of increase from there).
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LINKS
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Author?, Source
Author?, Source
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FORMULA
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a(n) would be proportional to 10^(0.6*n) in the simplifying hypothesis of a uniform distribution of identical stars in an infinite universe. Any empirical formula matching the actual sequence for n=0 to 10 is welcome.
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EXAMPLE
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There is 1 star brighter than -1 mag (Sirius, -1,44 mag). There are 4968 stars brighter than 6 mag, which is about the faintest brightness visible to the naked eye.
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CROSSREFS
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Cf. A072171.
Sequence in context: A052201 A099167 A056337 this_sequence A143215 A132308 A026110
Adjacent sequences: A053403 A053404 A053405 this_sequence A053407 A053408 A053409
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KEYWORD
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nonn,dumb
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AUTHOR
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Jean Fontaine (jfontain(AT)odyssee.net), Jan 08 2000
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