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  2. Mass–luminosity relation - Wikipedia

    en.wikipedia.org/wiki/Massluminosity_relation

    The relationship is represented by the equation: = where L ⊙ and M ⊙ are the luminosity and mass of the Sun and 1 < a < 6. [2] The value a = 3.5 is commonly used for main-sequence stars. [ 3 ] This equation and the usual value of a = 3.5 only applies to main-sequence stars with masses 2 M ⊙ < M < 55 M ⊙ and does not apply to red giants ...

  3. Mass-to-light ratio - Wikipedia

    en.wikipedia.org/wiki/Mass-to-light_ratio

    Mass-to-light ratios in application can be used to gain insight into the dark matter content and dust extinction in a galaxy. [4] Historically, rotation curves for spiral galaxies have been used to study galaxies, but mass-to-light ratios prove more accurate as a method of measuring mass. [5]

  4. Galaxy color–magnitude diagram - Wikipedia

    en.wikipedia.org/wiki/Galaxy_color–magnitude...

    A preliminary description of the three areas of this diagram was made in 2003 by Eric F. Bell et al. from the COMBO-17 survey [1] that clarified the bimodal distribution of red and blue galaxies as seen in the analysis of Sloan Digital Sky Survey data [2] and even in de Vaucouleurs's 1961 analyses of galaxy morphology. [3]

  5. Tully–Fisher relation - Wikipedia

    en.wikipedia.org/wiki/Tully–Fisher_relation

    The Tully–Fisher relation for spiral and lenticular galaxies. In astronomy, the Tully–Fisher relation (TFR) is a widely verified empirical relationship between the mass or intrinsic luminosity of a spiral galaxy and its asymptotic rotation velocity or emission line width. Since the observed brightness of a galaxy is distance-dependent, the ...

  6. Initial mass function - Wikipedia

    en.wikipedia.org/wiki/Initial_mass_function

    For example, the initial mass of a star is the primary factor of determining its colour, luminosity, radius, radiation spectrum, and quantity of materials and energy it emitted into interstellar space during its lifetime. [1] At low masses, the IMF sets the Milky Way Galaxy mass budget and the

  7. Cosmic distance ladder - Wikipedia

    en.wikipedia.org/wiki/Cosmic_distance_ladder

    The observational result of Hubble's law, the proportional relationship between distance and the speed with which a galaxy is moving away from us, usually referred to as redshift, is a product of the cosmic distance ladder. Edwin Hubble observed that fainter galaxies are more redshifted. Finding the value of the Hubble constant was the result ...

  8. Fundamental plane (elliptical galaxies) - Wikipedia

    en.wikipedia.org/wiki/Fundamental_plane...

    The fundamental plane is a set of bivariate correlations connecting some of the properties of normal elliptical galaxies.Some correlations have been empirically shown. The fundamental plane is usually expressed as a relationship between the effective radius, average surface brightness and central velocity dispersion of normal elliptical galaxies.

  9. Hertzsprung–Russell diagram - Wikipedia

    en.wikipedia.org/wiki/Hertzsprung–Russell_diagram

    The Sun is found on the main sequence at luminosity 1 (absolute magnitude 4.8) and B−V color index 0.66 (temperature 5780 K, spectral type G2V). The Hertzsprung–Russell diagram (abbreviated as H–R diagram , HR diagram or HRD ) is a scatter plot of stars showing the relationship between the stars' absolute magnitudes or luminosities and ...