Explanation:
A familiar sight for northern
hemisphere astronomers, the
Ring
Nebula (M57) is
some 2,000 light-years away in the musical
constellation
Lyra.
The central ring is about one light-year across, but
this remarkably deep exposure - a collaborative effort combining data
from two different telescopes -
explores
the looping filaments
of glowing gas extending much farther from the nebula's
central star.
Of course, in this well-studied
example of a
planetary nebula,
the glowing material does not come from planets.
Instead,
the gaseous shroud represents outer layers
expelled from a dying, sun-like star.
This composite image
includes over 16 hours of narrow-band data
intended to record the red emission from hydrogen atoms,
but the pronounced blue/green color is due to emission from
oxygen atoms at higher temperatures within the ring.
The much more distant spiral
galaxy IC 1296 is also visible at the upper right.
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