Sentences with phrase «luminosity relationship»

In her extensive studies of variable stars, Leavitt discovered the period - luminosity relationship, which ultimately helped calibrate a method to determine the size of the universe.

Of the red stars observed by Hertzsprung, the dwarf stars also followed the spectra - luminosity relationship discovered by Russell.

On average, main sequence stars are known to follow an empirical mass - luminosity relationship.

[44] For massive stars, however, this mass - luminosity relationship poorly matches the estimated lifetime.

This period - luminosity relationship can be used to deduce the distance of a star from its period of variation and its apparent brightness.

«Her discovery of the period - luminosity relationship in Cepheid variable stars is absolutely fundamental in transforming people's ideas about first, our own galactic system and second, providing the means to demonstrate that galaxies do in fact exist,» historian Robert Smith said in a talk last January.

Leavitt worked out the «period - luminosity relationship» in 1908, giving astronomers a powerful tool for measuring the distance to stars and other astronomical objects.

Not exact matches

Plotting the luminosity of the accretion disks against the gamma ray power of their jets, the team reports online today in Nature that there is a clear linear relationship between the two.

Another dynamical complication comes from the so - called Tully - Fisher relationship, which describes the relation between a galaxy's luminosity and its rotation velocity: the higher the luminosity, the faster a galaxy rotates.

Several methods are used, such as exploiting the known luminosities of old stars that are just beginning to burn Helium in their cores, and the relationship between the rotation speed of galaxies and the number of stars they possess.

This is the relationship between luminosity (L), radius (R) and temperature (T): L = (7.125 x 10 - 7) R2T4 where the units are defined as L - watts, R - meters and T - degrees Kelvin

If you apply the relationship between mass and luminosity to the H - R diagram, you find that stars along the main sequence vary from the highest (approximately 30 solar masses) at the top left to the lowest (approximately 0.1 solar mass) at the bottom right.

(Cepheid variables, named after Delta Cephei in Cepheus constellation, are very luminous stars that have a direct relationship between their luminosity and pulsation period, which makes these stars important standard candles for establishing distance scales.)

Her concentrated compositions engage the viewer in the contemplation of pure abstraction, in which colour relationships structure a luminosity that emanates, creating complex layers of space.

Zimbardo adds: «An interest in perception, luminosity, memory, and spatial relationships are themes that each artist develops to different ends.

The effect is in the ballpark of 5 %, since the sun is 30 % brighter than when it formed 4.5 billion years ago and the brightening trend accelerates as a star ages (A little educated guessing here, but the rate of fusion increases in proportion to the star's luminosity and the pressure needed in the core is an inverse relationship to the hydrogen concentration in the core — simple linear interpolation would give a 3.3 % increase in luminosity).