Complex sentence: The deep red color of Mu Cephei was noted by William Herschel, who described it as "a very fine deep garnet colour, such as the periodical star ο Ceti", and it was called "Garnet sidus" by Giuseppe Piazzi in his catalogue.
Split into simpler sentences: The deep red color of Mu Cephei was noted by William Herschel, who described it as "a very fine deep garnet colour, such as the periodical star ο Ceti". MuCephei was called "Garnet sidus" by Giuseppe Piazzi in his catalogue.