Explanation:
Cast off by dying sunlike stars,
planetary nebulae
are a brief but glorious final phase of stellar evolution.
The gaseous shrouds are ionized by an extremely hot central source,
the shrinking core of a star running out of
fuel for nuclear fusion.
Shining in the cosmic night, their simple
symmetries
are fascinating and have inspired this
planetary nebula poster project.
In it, nine planetaries are displayed for comparison in a 3x3 grid.
Of course, planetary nebula fans should be able to
pick out the bright
Messier objects
M27 - the Dumbbell Nebula,
M76 - the Little Dumbbell, and
M57 - the Ring Nebula, as well as
NGC 6543, aka the Cat's Eye Nebula.
Lesser known nebulae include the
Medusa and the
Bug.
All the images were made with detailed narrow band data and
are shown at the same
angular scale,
spanning 20 arc minutes (1/3 degree).
At that scale, the grey circle represents the apparent size of
the Full Moon.
These planetary nebulae
hint at the fate of our own
Sun as its core runs out of nuclear fuel in another
5 billion years.