

A053406


Number of stars brighter than visual magnitude n1.


1



1, 4, 15, 49, 172, 511, 1600, 4968, 15328, 40858, 82484, 106963, 114376, 116592, 117100, 117127, 117128, 117129
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OFFSET

0,2


COMMENTS

These numbers are not welldefined 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).


LINKS

Table of n, a(n) for n=0..17.
Author?, Source [Broken link?]
Author?, Source [Broken link?]


FORMULA

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.


EXAMPLE

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.


CROSSREFS

Cf. A072171.
Sequence in context: A178704 A099167 A056337 * A225265 A143215 A301973
Adjacent sequences: A053403 A053404 A053405 * A053407 A053408 A053409


KEYWORD

nonn,dumb


AUTHOR

Jean Fontaine (jfontain(AT)odyssee.net), Jan 08 2000


STATUS

approved



