A star's luminosity, which is how much energy is emitted per second from the star, is measured in Watts or in solar luminosities (L⊙) where 1L⊙ = 3.85 x 1026 Watt. We determine a star's luminosity by measuring its distance and its
What is luminosity and How Is It measured?
The luminosity of an object is a measure of its intrinsic brightness and is defined as the amount of energy the object emits in a fixed time. It is essentially the power output of the object and, as such, it can be measured in units such as Watts.
How is luminosity distance calculated?
More generally, the luminosity, apparent flux, and distance are related by the equation f = L/4`pi'd2. If we measure a star's parallax and its apparent brightness, we can determine its luminosity, which is an important intrinsic property.