Cygnus is a northern constellation on the plane of the Milky Way, deriving its name from the Latinized Greek word for swan. Cygnus is one of the most recognizable constellations of the northern summer and autumn, and it features a prominent asterism known as the Northern Cross. Cygnus was among the 48 constellations listed by the 2nd century astronomer Ptolemy, and it remains one of the 88 modern constellations.
Cygnus as depicted in Urania's Mirror, a set of constellation cards published in London c.1825. Surrounding it are Lacerta, Vulpecula and Lyra.
Cygnus is superimposed as main stars constellation over a photo of the according section of the night sky
On the left image side are the bright North America Nebula (left bright part) with Sadr region (right bright part) in the Cygnus X region, visually interrupted by the Cygnus rift, of the Cygnus constellation, in this x-ray image.
The constellation Cygnus as it can be seen by the naked eye, with the Northern Cross in the middle.
A deep-sky object (DSO) is any astronomical object that is not an individual star or Solar System object. The classification is used for the most part by amateur astronomers to denote visually observed faint naked eye and telescopic objects such as star clusters, nebulae and galaxies. This distinction is practical and technical, implying a variety of instruments and techniques appropriate to observation, and does not distinguish the nature of the object itself.