How do you measure absolute magnitude?

Answer 1

The absolute magnitude is the magnitude (brightness) an object would have at a standard distance - how bright would it look at a standard distance. For a star or galaxy, the standard distance of 10 parsecs is commonly used.

Answer 2

You look at the color of the light of the star and the "fraunhofer lines" which are teltale signs of the star's composition. You compare with theoretical models and other known stars of similar make-up, you thereby can know how bright it really shines (it's absolute magnitude)

Answer 3

M = m - 5 ((log10 DL) - 1)

• M = absolute magnitude,
• m = apparent magnitude.
• DL = Distance

For very large distances, redshift complicates might require a correction.

Answer 4

In astronomy, absolute magnitude measures a celestial object's intrinsic brightness as if all where viewed from the same distance. This distance is set at 1 AU for our Solar System. For greater distance's, galaxies etc. the value is 32.616 light years.

So our Sun has an Apparent magnitude (As viewed from Earth) of -26.74 (Negative values are the brightest) but it has an absolute magnitude of +4.83. Sirius for comparison has an absolute magnitude of +1.42 so would appear brighter if viewed from the same distance.

Answer 5

Absolute magnitude is a measure of the intrinsic brightness of a celestial object, independent of its distance from Earth. It is calculated as the apparent magnitude the object would have if it were placed at a standard distance of 10 parsecs (32.6 light-years) from Earth. This standard distance allows astronomers to directly compare the brightness of different objects.

Answer 6

You can't because you don't have enough information. The difference between the star's

absolute magnitude and apparent magnitude depends on its distance from earth.