Eridanus is a prominent constellation located in the southern sky. It is one of the largest constellations, stretching across an area of about 1,230 square degrees. The name "Eridanus" is derived from the ancient Greek word for a river, and it is often associated with the mythological river that flows through the underworld. The constellation contains several notable stars, including Achernar, which is one of the brightest stars in the night sky. Eridanus also features the Eridanus Supervoid, a vast region of space with fewer galaxies than expected, making it an interesting subject for astronomers studying the universe's structure.