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The mass/luminosity relationship can also be used to determine the lifetime of stars by noting that lifetime is approximately proportional to M/L although one finds that more massive stars have shorter lifetimes than that which the M/L relationship predicts. A more sophisticated calculation factors in a star's loss of mass over time.
Some stars visible to the naked eye have such a low absolute magnitude that they would appear bright enough to outshine the planets and cast shadows if they were at 10 parsecs from the Earth. Examples include Rigel (−7.8), Deneb (−8.4), Naos (−6.2), and Betelgeuse (−5.8).
The luminosity thus obtained is known as the bolometric luminosity. Masses are often calculated from the dynamics of the virialized system or from gravitational lensing . Typical mass-to-light ratios for galaxies range from 2 to 10 ϒ ☉ while on the largest scales, the mass to light ratio of the observable universe is approximately 100 ϒ ...
Asymptotic giant branch – Stars powered by fusion of hydrogen and helium in shell with an inactive core of carbon and oxygen; Galaxy color–magnitude diagram – Chart depicting the relationship between brightness and mass of large star systems; Hayashi track – Luminosity–temperature relationship in stars
Below about 0.5 M ☉, the luminosity of the star varies as the mass to the power of 2.3, producing a flattening of the slope on a graph of mass versus luminosity. Even these refinements are only an approximation, however, and the mass-luminosity relation can vary depending on a star's composition. [12]
Blue and white supergiants are high luminosity stars somewhat cooler than the most luminous main sequence stars. A star like Deneb, for example, has a luminosity around 200,000 L ⊙, a spectral type of A2, and an effective temperature around 8,500 K, meaning it has a radius around 203 R ☉ (1.41 × 10 11 m).
The paper concluded that there is a relation between spectral type and mass for stars. This was the first announcement of the mass–luminosity relation, later elaborated by many others. [ 8 ] His work on determination of magnitudes from photographic plates led him to an improved understanding of reciprocity failure, on which he published a ...
seen from Earth closest star (other than the Sun) +11.8 moon Phobos: seen from Earth Maximum brightness; brighter moon of Mars +12.23 star R136a1: seen from Earth Most luminous and massive star known [65] +12.89 moon Deimos: seen from Earth Maximum brightness +12.91: quasar 3C 273: seen from Earth brightest (luminosity distance of 2.4 billion ...