Hauntingly glowing in the darkness of space, ESO 378-1 cuts an eerie figure. Captured by the European Southern Observatory (ESO)’s Very Large Telescope in northern Chile, this is the best image yet of the planetary nebula.
ESO 378-1, which is nicknamed the Southern Owl Nebula, has a diameter of almost four light years. The planetary nebula earns its informal name due to its visual similarity with the Owl Nebula (M97), found in the Northern Hemisphere and located in the constellation of Ursa Major.
Planetary nebulae live a relatively short life, lasting only a few tens of thousands of years compared to a typical stellar lifetime of several billions of years. ESO 378-1, just like all planetary nebulae, was made by the gas from a dying star that has a mass less than eight times that of our Sun. The star’s ejected material continues to expand in space and it’s thanks to the ultraviolet radiation, which interacts with the surrounding gas, that causes the nebula to glow in bright colours.
Planetary nebulae don’t last forever though and they eventually fade away as a result of expanding further and further into space. The leftover stellar remnant at its centre will continue to burn for another billion years before consuming all of its remaining fuel. What’s then left is a tiny, hot and dense white dwarf that ever so slowly continues to cool for billions of years. Due to its low mass, the Sun will produce a planetary nebula billions of years from now and will also live out its life as a white dwarf.
Since they produce elements such as carbon and nitrogen as well as other heavier elements, planetary nebulae play a very important role in the chemical enrichment and evolution of the universe. They return material to the interstellar medium – the gas and dust found between the stars – that could eventually make new stars and planets suitable for life.