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Apparent Brightness[1]
Name Type Magnitude
Sun Fixed Star −26,8 mag
Moon Satellite −12,5 mag
TV-Satellites Man-made objects < −9,0 mag
Venus Planet −4,7 mag
Mars Planet −2,8 mag
Jupiter Planet −2,8 mag
Mercury Planet −1,9 mag
Sirius Fixed Star −1,4 mag
Canopus Fixed Star −0,73 mag
Saturn Planet −0,5 mag
Wega Fixed Star 0,0 mag[2]
Pole Star Fixed Star 2,0 mag
Uranus Planet 5,5 mag
Neptune Planet 7,8 mag
Pluto Dwarf Planet 14,0 mag
Part of Taurus[3]

Magnitude is a measure of relative brightness of heavenly bodies. Values for stars range from 1 for the brightest stars in the sky to 6 for those that are just visible to the naked eye.

Some of the planets are brighter than 1, and therefore are given negative values. The planet Uranus rates a 5.5, which under optimum viewing conditions is just barely visible to the naked eye; whereas Venus rates a -4.7.

This means, the larger the negative value, the brighter (cf. table).

The ancient Greeks first developed this system of classifying stars according to their magnitude. In science today the star Vega is defined to have an apparent magnitude of zero as measured through all filters.
Since the modern magnitude scale also is logarithmic, a magnitude 1 star is exactly a hundred times brighter than a magnitude 6 star.

See also


Notes and References

  1. Maximum, Johnson-V-Filter
  2. By definition
  3. Visibility of the constellation in the city up to 4 mag; in the mountains (clear sky) up to 6 mag