BRAINCAKEApparent Magnitude
The apparent magnitude, m, of a star measures how bright it appears from Earth. It depends on both the star's power output and its distance from us.
The scale comes from the ancient Greek Hipparcos scale: the brightest stars visible to the naked eye were given magnitude 1 and the faintest visible were given magnitude 6. So a smaller magnitude means a brighter star. The modern scale extends this to very bright objects, which have negative magnitudes (Sirius: m = −1.5; the Sun: m = −26.7), and to very faint objects seen through telescopes, with magnitudes well above 6.
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- Absolute Magnitude
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All 24 lessons in Astrophysics · All AQA A-level Physics topics