|
| |
|
|
A053406
|
|
Number of stars brighter than visual magnitude n-1.
|
|
1
|
|
|
|
1, 4, 15, 49, 172, 511, 1600, 4968, 15328, 40858, 82484, 106963, 114376, 116592, 117100, 117127, 117128, 117129
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
0,2
|
|
|
COMMENTS
|
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).
|
|
|
LINKS
|
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
|
|
|
|
KEYWORD
|
nonn,dumb
|
|
|
AUTHOR
|
Jean Fontaine (jfontain(AT)odyssee.net), Jan 08 2000
|
|
|
STATUS
|
approved
|
| |
|
|
