by Alan M. MacRobert, Sky and Telescope Magazine
- Rigel, Capella, Arcturus, and Vega are magnitude 0
- Sirius shines at magnitude –1.5
- Venus reaches –4.4
- Full Moon is about –12.5
- Sun blazes at magnitude –26.7.
Photometric Systems [UBVRI]
- Negative-Magnitudes (< 0)
- U encompasses the near-ultraviolet
- B is blue
- V corresponds fairly closely to the old visual magnitude
- Positive-Magnitudes (> 0)
- R standard red magnitudes
- I is near-infrared magnitudes.
Color Index (B magnitude minus the V magnitude) The difference between a star's photographic and visual magnitude
- positive for yellow, orange, and red stars,
- negative for blue ones."
Absolute Magnitude Scale
- An object's absolute magnitude is simply how bright it would appear if placed at a standard distance of 10 parsecs (32.6 light-years)