"Marfac," meaning the "Elbow." It is flanked on either side by a bright star, and in this respect resembles Altair, the first magnitude star in Aquila.
ε Persei is a double star, "especially interesting," says Serviss, "on account of an alleged change of colour from blue to red which the smaller star undergoes coincidently with a variation of brightness."
η Persei is also a double star, noteworthy as having three faint stars on one side nearly in a line and one on the other forming a miniature representation of Jupiter and his satellites.
ξ and ο Persei bear respectively the names "Menkib" and "Atik."
"The Milky Way around Perseus," says Burritt, "is very vivid, being undoubtedly a rich stratum of fixed stars, presenting the most wonderful and sublime phenomenon of the Creator's power and greatness." Kohler, the astronomer, observed a beautiful nebula near the face of Perseus, besides eight other nebulous clusters in different parts of the constellation.
About midway between β and δ Persei there appeared Feb. 21, 1901, a nova or new star. It was discovered by Dr. Anderson of Edinburgh and when first seen was of 2.5 magnitude. It shone with a bluish-white light and two days after its discovery it was brighter than Capella, having in three days increased its brightness 25,000 fold. All novæ are temporary and rapidly diminish in brightness. Following the usual course Nova Persei became invisible to the naked eye in six weeks and its spectrum soon became nebulous. So terrific was the heat evolved that the gases expanded outward with a velocity of over 2000 miles a second, and the distance was so great that its light only reached us after a period estimated at 300 years, hence the collision which we witnessed by the advent of this new star must have occurred about the year 1600.
Nova Persei was the most brilliant star that has appeared since 1604.
