Photometric parallax method

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The photometric parallax method is a method of data analysis used in astronomy that uses the colours and apparent brightnesses of stars to infer their distances. It was used by the Sloan Digital Sky Survey to discover the Virgo super star cluster.

Unlike the stellar parallax method, photometric parallax can be used to estimate the distances of stars over 10 kpc away, at the expense of much more limited accuracy for individual measurements. Strictly speaking, it does not actually employ any measurements of parallax and can be considered a misnomer.

Assuming that a star is on the main sequence, the star's absolute magnitude can be determined based on its color. Once the absolute and apparent magnitudes are known, the distance to the star can be determined by using the distance modulus.

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