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protoplanetary disk
Sign in to saveAlso known as proplyd, Proplyd or Protoplanetary Disc
rotating circumstellar disk of dense gas surrounding a young newly formed star
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Encyclopedic overview
Atacama Large Millimeter Array image of HL Tauri
A protoplanetary disk is a rotating circumstellar disc of dense gas and dust surrounding a young newly formed star, a T Tauri star, or Herbig Ae/Be star. The protoplanetary disk may not be considered an accretion disk; while the two are similar, an accretion disk is hotter and spins much faster, accreting matter onto a central body; it is also found on black holes, not only stars. This process should not be confused with the accretion process thought to build up the planets themselves. Externally illuminated photo-evaporating protoplanetary disks are called proplyds.
Excerpted from Wikipedia’s “protoplanetary disk” article, available under the CC BY-SA 4.0 licence.