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mass
subject			fact

mass	has unit mass unit
	has definition The quantitative property of an object due to the matter it contains. (Weight, in contrast, describes a force with which a body is attracted towards a gravitational focus.) Units of mass are grams and kilograms.
	has definition Measure of the amount of matter in an object. Inertial mass indicates the object's resistance to changes in its state of motion. Gravitational mass indicates its response to the gravitational force. In the general theory of relativity, gravitational and inertial mass are revealed to be aspects of the same quantity.
	has definition The measure of the inertia of an object, determined by observing the acceleration when a known force is applied. The gravitational force acting on an object is found to be proportional to its mass, as is the gravitational force that it exerts on other objects.
	is a kind of quantity
number	has value

Kinds of mass :

• atomic mass constant (9 facts) (m_u) - One-twelfth the mean mass of an atom of carbon 12 (including the orbital electrons).
• Chandrasekhar limit (3 facts) - A limiting mass for white dwarfs. If the mass exceeds this critical mass (1.44 solar masses, for the expected mean molecular weight of 2), the load of the overlying layers will be so great that degeneracy pressure will be unable to support it, and no configuration will be stable., The maximum mass, approximately 1.4 M_sun, above which an object cannot support itself by electron degeneracy pressure; hence, the maximum mass of a white dwarf.
• Chandrasekhar-Schonberg limit (3 facts) - Mass above which the helium core of a star begins to contract (eventually to collapse altogether). The limit is now reckoned as 10 to 15 per cent of the star's total mass., The mass limit for an isothermal core. In order to maintain its luminosity by hydrogen burning just outside the isothermal core, the star must keep a high temperature and a high pressure at the surface of the core. When the helium core exceeds about 12% of the star's total mass, the star can no longer adjust by small changes, but must drastically increase in radius and move rapidly from the main sequence.
• Eddington limit (2 facts) - In essence, radiation pressure must not exceed gravity. It is the limit beyond which the radiation force on matter in the emitting region is greater than the gravitational forces that hold the star together. L_E = 4πcGM/K_s, where K_s = Thomson and/or Compton scattering opacity. Eddington limit for a 1 M_sun star, 10³⁸ ergs s^-1.
• gravitational mass (2 facts) - That property of matter which makes it create a gravitational field and attract other particles (cf. inertial mass; equivalence principle).
• Jeans mass (3 facts) - The critical mass a volume of space must contain before it will collapse under the force of its own gravity., The mass enclosed within a sphere of diameter equal to the Jeans length.
• luminous mass (2 facts) - The mass contributed by luminous matter in galaxies (see missing mass). Luminous mass density, 5 × 10^-32 g cm^-3 for H₀ = 50 km s^-1 Mpc^-1.
• mass of the Galaxy (3 facts) - The mass of the Milky Way.
• particle mass (8 kinds, 43 facts)
• Planck mass (7 facts) (m_P) - About ten billion billion times the mass of a proton; about one-hundredth of a thousandth of a gram; about the mass of a small grain of dust. The typical mass equivalent of a vibrating string in string theory.