The famous Ring Nebula (also catalogued as Messier 57, M57 or NGC 6720) appears in the northern constellation of Lyra. It is a prominent example of a planetary nebula. This is a shell of ionized gas expelled into the surrounding interstellar medium by a red giant star, which was passing through the last stage in its evolution before becoming a white dwarf.
Read more about Ring Nebula: History, Observation, Properties
Famous quotes containing the word ring:
“When the merry bells ring round,
And the jocund rebecks sound
To many a youth and many a maid,
Dancing in the chequered shade;
And young and old come forth to play
On a sunshine holiday,”
—John Milton (1608–1674)