Object Analysis

The Retina Nebula (IC 4406) is a planetary nebula in the constellation Lupus. It is a bipolar nebula, and we are viewing it from its side, which gives it a distinct rectangular shape. It is located about 2,000 light-years away. The name "Retina" refers to the network of dark dust lanes that crisscross the bright central region, resembling the blood vessels in a human eye.

The dark dust lanes are actually the edges of a torus (donut shape) of dense material surrounding the dying central star. This torus funnels the hot gas outward in two opposite directions, creating the bipolar structure. The colors—red for nitrogen, green for oxygen, and blue for hydrogen—reveal the chemical layers of the star's former atmosphere.

If we could view the Retina Nebula from the top (the poles), it would likely look similar to the Ring Nebula (M57). Because it is seen edge-on, it provides astronomers with a unique side-view of the physics of gas expansion and the role that dust plays in shaping the final stages of a star's life.