ESO shares a close-up image of the Skull Nebula

I'm sure many people have looked up at the sky and tried to find the constellations over the centuries. Other than the Big Dipper and Little Dipper, most constellations don't look a lot like the objects they're supposed to for many people. The ESO has shared a new image from its Very Large Telescope of the Skull Nebula.

It doesn't take too much imagination to see the skull-like features of the nebula, which is also known as NGC 246. The nebula is about 1600 light-years from Earth in the southern constellation of Cetus (The Whale). The nebula formed when a sun-like star expelled its outer layers as it aged, leaving behind a white dwarf. The white dwarf remnant is one of the two stars at the very center of the nebula.

Interestingly, astronomers have known about the nebula for centuries, but a major discovery was made a few years ago. In 2014 when the Very Large Telescope was used to determine the white dwarf and its companion hide a third star in the heart of the Skull Nebula. That third star isn't visible in this image and is a red dwarf.

The red and white dwarf pair orbit each other while the outer star orbits the other two at a distance of around 1900 times that of the Earth-Sun separation. The trio of stars established NGC 246 as the first known planetary nebula with a hierarchical triple star system in its center. The material was taken using the FORS 2 instrument on the Very Large Telescope.

Astronomers intentionally captured light in narrow ranges of wavelengths for the image. Astronomers observe light emitted by particular elements to help determine information about chemical and structural compositions within the nebula. This particular image shows where the nebula is rich or poor in hydrogen, which shows as red, and oxygen, which shows as light blue.