The Crab Nebula,the most famous and conspicuous known supernova remnant,is an
expanding cloud of gas created in the explosion of a star. It shines as a nebula
of magnitude 8.4 near the southern "horn" of Taurus, the Bull.

The supernova was noted on July 4, 1054 A.D. by Chinese astronomers as a new
or "guest star," and was about four times brighter than Venus, or about mag -6.
According to the records, it was visible in daylight for 23 days, and for 653 days
to the naked eye in the night sky. It was probably also recorded by Anasazi Indian
artists (in present-day Arizona and New Mexico).