situated almost on the prime meridian; the other two guides are α Andromedæ and β Cassiopeiæ.
ε, ξ, η, and θ Pegasi bear respectively the following Arab names: "Enif," the nose, "Homam," the lucky star, "Matar," the fortunate rain, "Baham," the good luck of the two beasts.
Most of the faint stars in the constellation have received individual names, an indication of the importance of the constellation in early times.
Within the area of the Great Square Argelander counted about thirty naked eye stars, while Schmidt, observing at Athens, counted one hundred and two.
The writer acknowledges his indebtedness to Prof. W. W. Campbell, of the Lick Observatory, for the following information concerning the stars that form the Great Square of Pegasus:
Alpha Andromedæ is a spectroscopic binary star whose two components revolve around their mutual centre of mass in ninety-seven days, and the system as a whole is approaching the solar system with a speed of 13 km. per second.
Alpha Pegasi is a spectroscopic binary. The observed velocity is variable, and not enough observations have been secured to determine the velocity of the system.[1]
Midway between the head of the Flying Horse and the Dolphin, is a rectangular-shaped figure composed of fourth and fifth magnitude stars, which forms the asterism known as "Equuleus," "the Foal," "the Little Horse," or "the Horse's Head."
The head only of this equine figure is represented, and like the winged Horse appears in an inverted position.
Geminus mentions Equuleus as having been formed by Hipparchus. Ptolemy catalogued it as Ἴππον προτομή. The
- ↑ Beta Pegasi is receding from the solar system with a velocity of 8 km. per second. Gamma Pegasi is receding from the solar system with a velocity of 5 km. per second.
