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# Astronomical Albedo

EmilyB.Astronomical Albedo

The **Astronomical Albedo **calculator computes the astronomical albedo from the absolute magnitude of the object and the diameter.

**INSTRUCTION**: Choose units and enter the following:

- (
**H**) Absolute Magnitude - (
**D**) Diameter

**Astronomcial Albedo (A):** The calculator returns the albedo as a real number.

#### The Math / Science

Albedo is latin for whiteness. In astronomy, albedo is the measure of the diffuse reflection of light from a star (e.g. our Sun) of solar radiation compared to the total solar radiation received by an astronomical object (e.g. the Moon). The **Albedo (absolute magnitude and diameter)** or reflection coefficient is the diffuse reflectivity or reflecting power of a surface. It is the ratio of reflecting radiation from the surface to incident radiation upon it. Its dimensionless nature lets it be expressed as a percentage and is measured on a scale from zero for no reflection of a perfectly black surface to 1 for perfect reflection of a white surface.

The formula for astronomical albedo is:

`A=((1329·10^(-H/5))/D)^2`

where:

- A = astronomical albedo
- H = absolute magnitude
- D = diameter in kilometers

#### Astronomy Calculators

## References

Wikipedia (https://en.wikipedia.org/wiki/Albedo)