An extremely faint reflection nebula believed to be an ancient supernova remnant or gas cloud illuminated by nearby star Rigel in Orion which is the seventh brightest star in the sky.  It lies in the Eridanus constellation, about 900 light-years from Earth.   Eridanus constellation is located in the southern hemisphere. It represents a river. The constellation’s name is the Ancient Greek name for the river Po in Italy. In Sanskrit, it is called srotaswini, which means “stream,” “current,” or “torrent.”

The constellation Eridanus is associated with the myth of Phaëton and it is usually depicted as a river flowing from the waters poured by Aquarius.    Phaëton is best known was the son of the Oceanid Clymene and the solar deity Apollo or Helios. 

In the prevailing account, Phaethon, challenged by his playmates, sought assurance from his mother that his father was the sun god. She gave him the requested assurance and told him to turn to his father for confirmation. He asked his father for some proof that would demonstrate his relationship with the sun. When the god promised to grant him whatever he wanted, he insisted on being allowed to drive the sun chariot for a day. Placed in charge of the chariot, he was unable to control the horses. The earth was in danger of being burnt up and, to prevent this disaster, Zeus killed him with a thunderbolt. 

Jan Eyck: The Fall of Phaëton

The nature of the dust particles, reflecting blue light better than red, is a factor in giving the Witch Head its blue color.  

Discovered 1909 by the German astronomer Max Wolf.  

Rigel and the Witch Head Nebula