Astronomy Articles

The Visual Magnitude Scale

Visual brightness of stars, planets and other astronomical objects is based on the visual magnitude scale (Vo). Every integer increase in magnitude represents a 2.5 increase in brightness. So the Sun is 6 trillion times brighter than a 6th magnitude star, which in turn is 4 billion times brighter than a 30th magnitude star - the limit of the Hubble Space Telescope.

1. Magnitude (Vo)
2. Object or Limit

1. -27
2. the Sun

1. -20
2. brightest meteors

1. -13
2. Full Moon

1. -4
2. Venus

1. -2
2. Mars, Jupiter

1. -1
2. Sirius (brightest star)

1. +6
2. naked-eye limit

1. +10
2. binoculars limit

1. +14
2. 8" telescope limit

1. +15
2. 12" telescope limit

1. +18
2. 30" telescope limit

1. +25
2. large telescope limit (CCD)

1. +30
2. Hubble Space Telescope limit

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