Explanation:
A mere seven hundred light years from Earth, in the constellation
Aquarius,
a sun-like star is dying.
Its last few thousand years have produced the
Helix Nebula
(NGC 7293), a well studied and nearby example of a
Planetary Nebula,
typical of this final phase of stellar evolution.
Nearly 11 hours of exposure
time have gone in to creating this remarkably deep view of the nebula.
It shows details of the Helix's brighter
inner region, about 3
light-years across, but also follows fainter
outer halo features
that give the nebula a span of well over six light-years.
The white dot at the Helix's center is this Planetary Nebula's hot,
central star.
A simple looking nebula at first glance, the Helix
is now understood to have a surprisingly
complex geometry.
