Astronomy Picture of the Day

Explanation: This colorful telescopic viewtowards the musical northern constellation Lyrareveals the faint outer halos and brighter centralring-shaped region of M57,popularly known as theRing Nebula.To modern astronomers M57 is a well-knownplanetary nebula.With a central ring about one light-year across,M57 isdefinitely not a planet though, butthe gaseous shroud of one of the Milky Way'sdyingsun-like stars.Roughly the same apparent size as M57, the fainter andmore often overlooked barred spiral galaxy at the left is IC 1296.In fact, over 100 years agoIC 1296 would have been known as aspiral nebula.By chance the pair are in the same field of view, and while theyappear to have similar sizes they are actually very far apart.At a distance of a mere 2,000 light-yearsM57 is well within our own Milky Way galaxy.ExtragalacticIC 1296 (aka PGC62532) is more like 200,000,000 light-years distant.That's about 100,000 times farther away than M57but since they appear roughly similar in size, former spiral nebula IC 1296must also be about 100,000times larger than planetary nebula M57.Look closely at the sharp 21st century astroimage to spoteven more distant background galaxiesscattered through the frame.