Eerie Skull Nebula glows bright for Halloween

A spooky new image captures the Skull Nebula illuminated by a triple star system just in time for Halloween.

The Skull Nebula, formally known as NGC 246, is located roughly 1,600 light-years away in the constellation Cetus, or The Whale. Using the Very Large Telescope in Chile, the European Southern Observatory (ESO) snapped a new photo of the eerie nebula, which bears a striking resemblance to a skull floating through space.

NGC 246 is a planetary nebula that consists of a pair of closely bound stars orbited by a third outer star. The nebula is the dusty remnant of a stellar explosion, during which a sun-like star expelled its outer layers, leaving behind a glowing white dwarf star.

The bright white dwarf is one of two stars that can be seen at the very center of NGC 246. However, the white dwarf also has a dim red dwarf stellar companion that can’t be seen in the new ESO image. These two stars orbit each other as a binary pair, which is in turn orbited by a third star at a distance of about 1,900 times the space between Earth and the sun.

“Collectively, these three stars establish NGC 246 as the first known planetary nebula with a hierarchical triple stellar system at its center,” according to a statement from the ESO.

The new image was taken using the FOcal Reducer and low dispersion Spectrograph 2, or FORS2, instrument mounted on Antu — one of the VLT’s telescopes at the Paranal Observatory.

The new view of the Skull Nebula captures the bloodshot clouds of gas and dust that remain from the stellar explosion. The hydrogen (red) and oxygen (light blue) gases of the nebula appear to glow, illuminating the skull’s face against the dark backdrop of interstellar space.