accretion
Quick Summary
Accretion is the process by which astronomical objects grow by gravitationally attracting and accumulating surrounding material. This material, often gas, plasma, or dust, forms a disk around the central object, known as an accretion disk. Within this disk, the material loses energy and angular momentum, causing it to spiral inward towards the central object, or "accretor".12
Accretion disks are crucial in astrophysics, playing a role in the formation of stars and planets. They are also responsible for powering some of the most energetic phenomena in the universe, such as quasars and X-ray binaries, by converting gravitational potential energy into radiation. The accretor can range from a forming star or planet to compact objects like neutron stars and black holes.13
Ask Britannica AI about this topic
Britannica doesn't have a full article on this topic, so we've curated a list of our relevant coverage.
accretion diskIn astrophysics, the term accretion refers to the growth in mass of any celestial object due to its gravitational attraction. The formation of stars and planets and the powerful emissions from quasars, radio galaxies, X-ray binaries
Read MoreIn astrophysics, the term accretion refers to the growth in mass of any celestial object due to its gravitational attraction. The formation of stars and planets and the powerful emissions from quasars, radio galaxies, X-ray binaries
Read More- asteroidOrigin and evolution of the asteroids
Dynamical models suggest that during the first million years after the formation of the solar system, gravitational interactions among the giant planets (Jupiter, Saturn, Uranus, and Neptune) and the remnants of the primordial accretion disk resulted in
Read MoreDynamical models suggest that during the first million years after the formation of the solar system, gravitational interactions among the giant planets (Jupiter, Saturn, Uranus, and Neptune) and the remnants of the primordial accretion disk resulted in
Read More 
EarthAccretion of the early EarthAs the gas making up the solar nebula beyond the Sun cooled with time, mineral grains are thought to have condensed and aggregated to form the earliest meteoritic material. In addition, as is suggested by the finding of anomalous concentrationsā¦
Read MoreAs the gas making up the solar nebula beyond the Sun cooled with time, mineral grains are thought to have condensed and aggregated to form the earliest meteoritic material. In addition, as is suggested by the finding of anomalous concentrationsā¦
Read More
meteoriteā¦have involved more than simple aggregation, but their moonsāand cometsāprobably did form by this basic mechanism. Available evidence indicates that asteroids and comets are leftovers of the intermediate stages of the aggregation mechanism. They are therefore representative of bodies that formed quite early in the history of the solar system.ā¦
Read Moreā¦have involved more than simple aggregation, but their moonsāand cometsāprobably did form by this basic mechanism. Available evidence indicates that asteroids and comets are leftovers of the intermediate stages of the aggregation mechanism. They are therefore representative of bodies that formed quite early in the history of the solar system.ā¦
Read More
solar systemLater stages of planetary accretionContinued growth by accretion leads to larger and larger objects. The energy released during accretionary impacts would be sufficient to cause vaporization and extensive melting, transforming the original primitive material that had been produced by direct condensation in the nebula. Theoretical studies of thisā¦
Read MoreContinued growth by accretion leads to larger and larger objects. The energy released during accretionary impacts would be sufficient to cause vaporization and extensive melting, transforming the original primitive material that had been produced by direct condensation in the nebula. Theoretical studies of thisā¦
Read More