45 relations: Accretion (astrophysics), Astronomical object, Big Crunch, Binary star, Black dwarf, Black hole, Cambridge University Press, Carbon detonation, Chandrasekhar limit, Cosmic censorship hypothesis, Degenerate matter, Dynamic equilibrium, Electron degeneracy pressure, Event horizon, Galaxy formation and evolution, General relativity, Gravitational singularity, Gravitational wave, Gravity, Hydrostatic equilibrium, Interstellar medium, Jeans instability, Kerr metric, Kinetic energy, Matter, Neutron star, Planck units, Planet, Planetary nebula, Potential energy, Pressure, Roger Penrose, Schwarzschild metric, Schwarzschild radius, Solar mass, Star formation, Stellar evolution, Strong interaction, Thermal runaway, Thermonuclear fusion, Tolman–Oppenheimer–Volkoff limit, Type Ia supernova, Type II supernova, Virial theorem, White dwarf.
In astrophysics, accretion is the accumulation of particles into a massive object by gravitationally attracting more matter, typically gaseous matter, in an accretion disk.
An astronomical object or celestial object is a naturally occurring physical entity, association, or structure that exists in the observable universe.
The Big Crunch is one possible scenario for the ultimate fate of the universe, in which the metric expansion of space eventually reverses and the universe recollapses, ultimately causing the cosmic scale factor to reach zero or causing a reformation of the universe starting with another Big Bang.
A binary star is a star system consisting of two stars orbiting around their common barycenter.
A black dwarf is a theoretical stellar remnant, specifically a white dwarf that has cooled sufficiently that it no longer emits significant heat or light.
A black hole is a region of spacetime exhibiting such strong gravitational effects that nothing—not even particles and electromagnetic radiation such as light—can escape from inside it.
Cambridge University Press (CUP) is the publishing business of the University of Cambridge.
Carbon detonation or Carbon deflagration is the violent reignition of thermonuclear fusion in a white dwarf star that was previously slowly cooling.
The Chandrasekhar limit is the maximum mass of a stable white dwarf star.
The weak and the strong cosmic censorship hypotheses are two mathematical conjectures about the structure of singularities arising in general relativity.
Degenerate matter is a highly dense state of matter in which particles must occupy high states of kinetic energy in order to satisfy the Pauli exclusion principle.
In chemistry, a dynamic equilibrium exists once a reversible reaction ceases to change its ratio of reactants/products, but substances move between the chemicals at an equal rate, meaning there is no net change.
Electron degeneracy pressure is a particular manifestation of the more general phenomenon of quantum degeneracy pressure.
In general relativity, an event horizon is a region in spacetime beyond which events cannot affect an outside observer.
The study of galaxy formation and evolution is concerned with the processes that formed a heterogeneous universe from a homogeneous beginning, the formation of the first galaxies, the way galaxies change over time, and the processes that have generated the variety of structures observed in nearby galaxies.
General relativity (GR, also known as the general theory of relativity or GTR) is the geometric theory of gravitation published by Albert Einstein in 1915 and the current description of gravitation in modern physics.
A gravitational singularity or spacetime singularity is a location in spacetime where the gravitational field of a celestial body becomes infinite in a way that does not depend on the coordinate system.
Gravitational waves are the disturbance in the fabric ("curvature") of spacetime generated by accelerated masses and propagate as waves outward from their source at the speed of light.
Gravity, or gravitation, is a natural phenomenon by which all things with mass or energy—including planets, stars, galaxies, and even light—are brought toward (or gravitate toward) one another.
In fluid mechanics, a fluid is said to be in hydrostatic equilibrium or hydrostatic balance when it is at rest, or when the flow velocity at each point is constant over time.
In astronomy, the interstellar medium (ISM) is the matter and radiation that exists in the space between the star systems in a galaxy.
In stellar physics, the Jeans instability causes the collapse of interstellar gas clouds and subsequent star formation.
The Kerr metric or Kerr geometry describes the geometry of empty spacetime around a rotating uncharged axially-symmetric black hole with a spherical event horizon.
In physics, the kinetic energy of an object is the energy that it possesses due to its motion.
In the classical physics observed in everyday life, matter is any substance that has mass and takes up space by having volume.
A neutron star is the collapsed core of a large star which before collapse had a total of between 10 and 29 solar masses.
In particle physics and physical cosmology, Planck units are a set of units of measurement defined exclusively in terms of five universal physical constants, in such a manner that these five physical constants take on the numerical value of 1 when expressed in terms of these units.
A planet is an astronomical body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and has cleared its neighbouring region of planetesimals.
A planetary nebula, abbreviated as PN or plural PNe, is a type of emission nebula consisting of an expanding, glowing shell of ionized gas ejected from red giant stars late in their lives.
In physics, potential energy is the energy possessed by an object because of its position relative to other objects, stresses within itself, its electric charge, or other factors.
Pressure (symbol: p or P) is the force applied perpendicular to the surface of an object per unit area over which that force is distributed.
Sir Roger Penrose (born 8 August 1931) is an English mathematical physicist, mathematician and philosopher of science.
In Einstein's theory of general relativity, the Schwarzschild metric (also known as the Schwarzschild vacuum or Schwarzschild solution) is the solution to the Einstein field equations that describes the gravitational field outside a spherical mass, on the assumption that the electric charge of the mass, angular momentum of the mass, and universal cosmological constant are all zero.
The Schwarzschild radius (sometimes historically referred to as the gravitational radius) is a physical parameter that shows up in the Schwarzschild solution to Einstein's field equations, corresponding to the radius defining the event horizon of a Schwarzschild black hole.
The solar mass is a standard unit of mass in astronomy, equal to approximately.
Star formation is the process by which dense regions within molecular clouds in interstellar space, sometimes referred to as "stellar nurseries" or "star-forming regions", collapse and form stars.
Stellar evolution is the process by which a star changes over the course of time.
In particle physics, the strong interaction is the mechanism responsible for the strong nuclear force (also called the strong force or nuclear strong force), and is one of the four known fundamental interactions, with the others being electromagnetism, the weak interaction, and gravitation.
Thermal runaway occurs in situations where an increase in temperature changes the conditions in a way that causes a further increase in temperature, often leading to a destructive result.
Thermonuclear fusion is a way to achieve nuclear fusion by using extremely high temperatures.
The Tolman–Oppenheimer–Volkoff limit (or TOV limit) is an upper bound to the mass of cold, nonrotating neutron stars, analogous to the Chandrasekhar limit for white dwarf stars.
A type Ia supernova (read "type one-a") is a type of supernova that occurs in binary systems (two stars orbiting one another) in which one of the stars is a white dwarf.
A Type II supernova (plural: supernovae or supernovas) results from the rapid collapse and violent explosion of a massive star.
In mechanics, the virial theorem provides a general equation that relates the average over time of the total kinetic energy, \left\langle T \right\rangle, of a stable system consisting of N particles, bound by potential forces, with that of the total potential energy, \left\langle V_\text \right\rangle, where angle brackets represent the average over time of the enclosed quantity.
A white dwarf, also called a degenerate dwarf, is a stellar core remnant composed mostly of electron-degenerate matter.