|Sun||Fixed Star||−26,8 mag|
|TV-Satellites||Man-made objects||< −9,0 mag|
|Sirius||Fixed Star||−1,4 mag|
|Canopus||Fixed Star||−0,73 mag|
|Wega||Fixed Star||0,0 mag|
|Pole Star||Fixed Star||2,0 mag|
|Pluto||Dwarf Planet||14,0 mag|
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.
Notes and References
- Maximum, Johnson-V-Filter
- By definition
- Visibility of the constellation in the city up to 4 mag; in the mountains (clear sky) up to 6 mag