Astronomy: Accretion Disks

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Accretion Disks An accretion disk is a structure (often a circumstellar disk) formed by diffuse material in orbital motion around a massive central body. The central body is most frequently a star.

Commentary

Accretion Disks An accretion disk is a structure (often a circumstellar disk) formed by diffuse material in orbital motion around a massive central body. The central body is most frequently a star. Friction, uneven irradiance, magnetohydrodynamic effects, and other forces induce instab ilities causing orbiting material in the disk to spiral inward toward the central body. Why Accretion Disks matters: These foundational ideas and techniques are the tools astronomers use to measure, classify, and understand everything from nearby planets to the most distant galaxies. Gravitational and frictional forces compress and raise the temperature of the material, causing the emission of electromagnetic radiation. The frequency range of that radiation depends on the central object's mass. Accretion disks of young stars and protostars radiate in the infrared; those around neutron stars and black holes in the X-ray part of the spectrum. The study of oscillation modes in accretion disks is referred to as diskoseismology. Deep dive: Accretion Disks The frequency range of that radiation depends on the central object's mass. Accretion disks of young stars and protostars radiate in the infrared; those around neutron stars and black holes in the X-ray part of the spectrum. The study of oscillation modes in accretion disks is referred to as diskoseismology. Source: https://en.wikipedia.org/wiki/Accretion_disk (Wikipedia, CC BY-SA)

Sources: Wikipedia (CC BY-SA)