Gas looks so pretty in space, don't you agree?

This particular stellar gas is named planetary nebula ESO 456-67 . Do not get the wrong idea reading 'planetary'. This celestial object has nothing to do with planets. Back in the days when telescopes provided less resolution than the ones we have today, it looked pretty small and hence was named planetary nebulae (as opposed to the bigger stars). What it really is, are shells with gas after stars fling them off towards the end of their lives. Check out the lives of stars here in the Hertzprung-Russell diagram. What is left after the star got rid of this gas is a small dense white dwarf.

It is quite lovely, really.

Planetary nebula ESO 456-67
Planetary nebula ESO 456-67. Credit: ESA/Hubble&NASA. Acknowledgement: Jean-Christophe Lambry