A measure of the rate of energy flowing from a source, such as a galaxy, star, or light bulb. Luminosity tells astronomers how fast energy "leaks" from the star. It is a measure of power, and it is measured in units called watts. Given the luminosity of a star, an astronomer can calculate the distance to the star by measuring the star's brightness. Luminosity is also related to temperature, mass and size of a star.
of a star depends upon the area of the star's surface (opaque radiating layer of gases) and upon the fourth power of its surface temperature. The luminosity of a star is a measure of its energy output, it can be known directly, as opposed to inferred, only if the star's distance can be measured.
the amount of energy radiated per second by a body. For example, the wattage of a light bulb defines its luminosity. Stellar luminosity is usually measured in units of the Sun's luminosity, approximately 4X1026 watts.
The amount of energy radiated into space per second by a star. The bolometric luminosity is the total amount of radiation at all frequencies; sometimes luminosity is given for a specific band of frequencies (e.g. the visual band).
the amount of energy emitted by an object per second. As with flux, luminosities can be monochromatic, bolometric or integrated over a finite frequency range. Note that astronomers often quote bolometric luminosities in units of the Sun's luminosity (L/Lsun) rather than in watts.
A value corresponding to the brightness of a color. A yellow street sign photographed at dusk would have low luminance, or luminosity. That same sign, photographed at 2 p.m. on a sunny day, would have high luminosity. If a cloud comes by and covers that bright sun, the yellow in the sign would exhibit medium luminance.
A measure of the rate of energy flowing from a source, like a galaxy, star, or light bulb. Luminosity tells astronomers how fast energy "leaks" from the star. Luminosity is a measure of power divided into units called watts. Given the luminosity of a star, an astronomer can calculate the distance to the star by measuring the star's brightness. Temperature and luminosity are related, but dependent on the mass and size of a star. See also: temperature
Luminosity is the total brightness of a star (or galaxy). Luminosity is the total amount of energy that a star radiates each second (including all wavelengths of electromagnetic radiation). The Sun is a as a G2V type star.