Cygnus

Cygnus (abbreviation Cyg), the Swan, is a conspicuous northern constellation that lies east of Lyra and north of Vulpecula. The main stars form a cruciform asterism known as the Northern Cross – a familiar sight overhead in northern winter evening skies. See below for details of the constellation's brightest stars and interesting deep sky objects.

The Northern Cross is an asterism consisting of five bright stars that make up the most prominent part of Cygnus. These stars are: Deneb (Alpha Cyg), Albireo (Beta Cyg), Sadr (Gamma Cyg), Delta Cyg, and Gienah (Epsilon Cyg).

Cygnus A

Cygnus A (3C 405) is the strongest extragalactic radio source and third strongest radio source in the sky (after the Sun and Cassiopeiae A). At one time believed to be the result of a collision of two galaxies, it has now been identified as a classic double-lobed radio galaxy that, at optical wavelengths, is a 15th magnitude cD galaxy (a supergiant elliptical) lying about one billion light-years away.

Brightest stars and other objects of interest in Cygnus

Stars in Cygnus brighter than magnitude 4.0
star	vis mag	abs mag	spec type	distance (ly)	RA (h m s)	Dec (° ' ")
Alpha (Deneb)	1.25	-8.73	A2Iae	3,230	20 41 26	+45 16 49
Gamma (Sadr)	2.23	-6.12	F8Ib	1,520	20 22 14	+40 15 24
Epsilon (Gienah)	2.58	-0.94	K0III	165	20 46 13	+33 58 13
Delta	2.86	-0.74	B9.5IV+F1V	171	19 44 58	+45 07 51
Beta (Albireo)	3.05	-2.32	K3II+B0.5V	386	19 30 43	+27 57 35
Zeta	3.21	-0.12	G8III-IIIaBa	151	21 12 56	+30 13 37
Xi	3.72	-4.07	K5Ib-II	1,180	21 04 56	+43 55 40
Tau	3.73	2.13	F1IV	68	21 14 47	+38 02 44
Iota	3.76	0.88	A5Vn	122	19 29 42	+51 43 47
Kappa	3.80	0.91	K0III	123	19 17 06	+53 22 07
Eta	3.89	0.73	K0III	139	19 56 18	+35 05 00
Nu	3.94	-1.25	A1Vn	356	20 57 10	+41 10 02

Other objects of interest
name	type of object	notes
61 Cygni	star	See separate entry
P Cygni	star	The prototype P Cygni star
SS Cygni	star	The prototype SS Cygni star
Cygnus X-1	star	See separate entry
Blinking Nebula	planetary nebula	NGC 6826. See separate entry
NGC 7072	planetary nebula	An object with an irregular shape and four bright condensations. Magnitude 13.9; diameter 0.8'; RA 21h 30.6m, Dec -43° 09'
NGC 6960, 6992	diffuse nebula	The western and eastern parts, respectively, of the Veil Nebula
North America Nebula	diffuse nebula	NGC 7000. See separate entry
Pelican Nebula	diffuse nebula	IC 5067, 5070. See separate entry
Great Rift	dark nebula	See separate entry
M29 (NGC 6913)	open cluster	A cluster of about 50 stars near Gamma Cyg. Magnitude 6.6; diameter 7'; RA 20h 23.9m, Dec +48° 26'.
M39 (NGC 7092)	open cluster	About 50 stars in a loose grouping about 9° east and slightly north of Deneb. Magnitude 4.6; diameter 32'; RA 21h 32.2m, Dec +44° 20'.