A circumstellar disk is a torus, pancake or ring-shaped accumulation of matter composed of gas, dust, planetesimals, asteroids or collision fragments in orbit around a star. Around the youngest stars, they are the reservoirs of material out of which planets may form. Around mature stars, they indicate that planetesimal formation has taken place and around white dwarfs, they indicate that planetary material survived the whole of stellar evolution. Such a disk can manifest itself in various ways.
Read more about Circumstellar Disk: Young Star, Belt or Cloud, Binary System, Dust
Famous quotes containing the word disk:
“Unloved, that beech will gather brown,
This maple burn itself away;
Unloved, the sun-flower, shining fair,
Ray round with flames her disk of seed,
And many a rose-carnation feed
With summer spice the humming air;”
—Alfred Tennyson (1809–1892)