Explanation:
Planetary nebulae can look simple,
round, and planet-like in small telescopes.
But images from the orbiting
Hubble Space Telescope have become
well known for showing these fluorescent
gas shrouds of dying Sun-like stars to possess a
staggering variety
of detailed symmetries and shapes.
This composite color Hubble
image of NGC 6751 is a beautiful example of a
classic planetary nebula with complex features.
It was selected in April of 2000, to commemorate the
tenth
anniversary of Hubble in orbit.
The colors were chosen to represent the relative temperature of the
gas - blue, orange, and red indicating the hottest to coolest gas.
Winds and radiation from the intensely hot central
star
(140,000 degreesCelsius)
have apparently created the nebula's streamer-like features.
The nebula's
actual diameter is approximately 0.8 light-years
or about 600 times the size of our solar system.
NGC 6751 is 6,500 light-years distant in the high-flying constellation
Aquila.
