In 1996, NASA Hubble revealed the hourglass shape of this young planetary nebula about 8000 light-years away. In earlier images taken from the ground, the nebula appeared as two large outer rings surrounded by a smaller center, but fine details were not discernible.

Planetary nebulae form when stars similar to the Sun die. The star collapses and forms a dense, hot white dwarf star. At the same time, the dying star sheds its outer layers to form a complex cloud of gas and dust called a planetary nebula. While this is not uncommon, this “eye” nebula is a little different: While it should be in the center of the nebula, it is located off-center.

Hubble has also discovered new and surprising features within the nebula. In the center, for example, there are two intersecting elliptical rings that resemble the sides of a smaller hourglass. In addition, the walls of the hourglass are engraved with intricate patterns. There are several possible explanations for these arc-shaped grooves; for example, they could be the remnants of shells ejected when the star was younger.

This image is a composite of three different images taken with Hubble's Wide Field and Planetary Camera 2. The images were taken under ionized nitrogen (red), hydrogen (green) and double ionized oxygen (blue) light.

Image description:

This nebula has an interesting appearance: what looks like a turquoise-blue eye stares back at you from the center of a red-orange hourglass-like shape made up of two nested circles - like a Venn diagram turned on its side. Inside each of the circles are arcs. The darkness of space forms the background of this image.

 

Credit: NASA/JPL-Caltech/ESA, Hubble Legacy Team STScI/AURA