What Are the Standard Units of Measure for Luminosity?

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The common term of measurement for luminosity is watts. Luminosity is the measure of brightness and the amount of energy a star or light emits per second. The measurement is an intrinsic measurable property that can be made independently of distance.

Watts measure the amount of energy that is coming from a light. This is the most used and familiar measurement. It is seen on packages of light bulbs and other various light units. Most wattage measurements are based on the luminosity of the sun, which is 3.9 x 10 to the 26th power wherever it is observed from. Used in these measurements, luminosity is measured in two forms: visible light and bolometric. Bolometric is the total radiant energy, and when not specified, luminosity refers to bolometric luminosity.

In astrology, luminosity of a star can be calculated by using two stellar characteristics: the size of the star and the effective temperature. The size is represented by the term solar radii and the temperature by the measurement of kelvins. These factors can't be measured directly, so astrologists use the stars' angular diameters and the distances from earth. The angular diameter cannot be measured exactly, so all of these measurements are estimated. Despite these measurements being estimations, by using a standardized process like this, scientists can get stable results every time.