The Skull Nebula, NGC 246, is a planetary nebula in Cetus whose hot central star belongs to a multiple system and whose shell ploughs through interstellar gas.
At a glance
| type | nebula |
|---|---|
| distance from the Sun | 1,830 light-years (560 pc) |
| its light left it | 1,830 years ago |
| size in the piece | about 1.2 light-years acrossmodel |
Read off the piece’s own catalogue, the same values it draws with. Model marks a property of the piece’s galaxy model rather than a measurement.
About Skull Nebula
NGC 246 is a planetary nebula: a shell of gas shed by a dying star, glowing because the exposed stellar core floods it with ultraviolet light. Its dark patches against the bright shell give it the look of a face or skull, hence the nickname. It lies in Cetus, well away from the Milky Way’s plane, and is large and faint for a planetary nebula, a sign that it is relatively old and has had time to spread out.
The central star is a hot, hydrogen-poor white dwarf in the making, and it does not sit alone. A brighter companion is visible beside it, and observations with the Very Large Telescope revealed a further star close to the nucleus, making this a rare planetary nebula with a triple star at its heart. The whole system is moving through the surrounding gas, which brightens the side of the shell facing its direction of travel.
What you see in the piece
In the piece it is a small cloud of glowing gas well below the plane of the disc, too faint and too small to see from the Sun’s neighbourhood without flying to it.
Questions
Why is it called the Skull Nebula?
The dark gaps inside its glowing shell resemble the eye sockets and mouth of a skull or face when seen in photographs.
How far away is the Skull Nebula?
The Skull Nebula is 1,830 light-years (560 pc) from the Sun.