Witch Head Nebula

IC 2118 / Witch Head Nebula is a faint reflection nebula formed from an ancient supernova, illuminated by the blue supergiant Rigel (β Orionis). The gas cloud is located in the constellation of Eridanus at a distance of 900 light-years.
The nebula is rich in carbon monoxide, which is a sign of molecular clouds and star-forming events. Many T-Tauri objects have been observed within the nebula – very young variable stars, which are in the contraction stage before entering the main sequence. Their core is not hot enough to fuse hydrogen, but during the contraction phase, the increase in temperature allows for the fusion to start.
The bluish hue of the nebula is due to the dust particles which reflect more efficient the light from Rigel. The maximum length of IC 2118 is 70 light-years. Apparently, near the nebula we can find the star called Cursa (β Eridani), but this is only 90 light-years away.