Pegasus

Pegasus (abbreviation: Peg), the Winged Horse, is a large northern constellation. Alpha, Beta, and Gamma Peg, together with Alpha Andromedae (which was originally Delta Peg), form the Square of Pegasus. The most prominent deep-sky object is the globular cluster M15 (NGC 7078), one of the densest of its type and notable for its many variable stars and pulsars (magnitude 6.3; diameter 12.3 arcminutes; RA 21h 30.0m, Dec +12° 10'). Binoculars and small telescopes show it as a misty patch; telescopes of at last 15-centimeter aperture resolve individual stars. See below for details of the constellation's brightest stars.

Square of Pegasus

The Square of Pegasus is a large, approximate square of conspicuous stars in an otherwise barren part of the northern sky. Three of the corner-stars, Markab, Scheat and Algenib, belong Pegasus. The fourth, Sirrah, was lost to Pegasus when the constellation boundaries were formalised, and now lies just within the borders of Andromeda.

Stars brighter than magnitude 4.0
star	vis mag	abs mag	spec type	distance (ly)	RA (h m s)	Dec (° ' ")
Epsilon (Enif)	2.38	-4.19	K2Ib	673	21 44 11	+09 52 30
Beta (Scheat)	2.44	-1.49	M2.5II	199	23 03 46	+28 04 58
Alpha (Markab)	2.49	-0.67	B9III	140	23 04 46	+15 12 19
Gamma (Algenib)	2.83v	-2.22	B2IV	333	00 13 14	+15 11 01
Eta (Matar)	2.93	-1.17	G2II+F0V	215	22 43 00	+30 13 17
Zeta (Homan)	3.41	-0.62	B8V	209	22 41 28	+10 49 53
Mu (Sadalbari)	3.51	0.74	M2III	117	22 50 00	+24 36 06
Theta (Biham)	3.52	1.16	A2V	97	22 10 12	+06 11 52
Iota	3.77	3.42	F5V	38	22 07 01	+25 20 42