Your guide to the Solar System and the night sky
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🌎  Greenwich, United Kingdom [change]

Deneb - α Cygni (alpha Cygni)

Deneb, also designated as α Cygni (alpha Cygni), is a variable and double supergiant star in the constellation of Cygnus.

Deneb visual magnitude is 1.25, making it the 18th brightest star in the sky. Thanks to its high brightness, Deneb is clearly visible when observed from locations with dark skyes, and should be also quite easily visible from light polluted areas.

The table below summarizes the key facts about Deneb:

1.25
Supergiant
Deneb - α Cygni (alpha Cygni) is above the horizon from Greenwich, United Kingdom [change]. Altitude: 34°.

Celestial coordinates and finder chart of Deneb

Deneb is situated north of the celestial equator, as such, it is more easily visible from the northern hemisphere. Celestial coordinates for the J2000 equinox as well as galactic coordinates of Deneb are provided in the following table:

20h 41m 25s
+45° 16’ 49”
84.28°
Cygnus

The simplified sky map below shows the position of Deneb in the sky:

Finder chart Deneb - α Cygni (alpha Cygni) star
Simplified finder chart for Deneb - α Cygni (alpha Cygni).

Visibility of Deneb from your location

Location: Greenwich, United Kingdom [change]
Latitude: 51° 28’ 47” N
Longitude: 0° 00’ 00” E
Timezone: Europe/London

Deneb - α Cygni (alpha Cygni) is circumpolar and transits at 12:49 UTC (altitude: 83.8°)

Digitized Sky Survey image of Deneb

The image below is a photograph of Deneb from the Digitized Sky Survey 2 (DSS2 - see the credits section) taken in the red channel. The area of sky represented in the image is 0.5x0.5 degrees (30x30 arcmins). The proper motion of Deneb is 0.003 arcsec per year in Right Ascension and 0.002 arcsec per year in Declination and the associated displacement for the next 100000 years is represented with the red arrow.

Image of Deneb - α Cygni (alpha Cygni) star
DSS2 image of Deneb. The red arrow shows the motion of Deneb during the next 100000 years (5.00 arcmin in Right Ascension and 3.33 arcmin in declination);

Distance of Deneb from the Sun and relative movement

Deneb is distant 3,227.72 light years from the Sun and it is moving towards the Sun at the speed of 5 kilometers per second.

990.10 pc
3,227.72 ly
-5 km/s
0.003 arcsec/year
0.002 arcsec/year

Spectral properties of Deneb

Deneb belongs to spectral class A2 and has a luminosity class of I corresponding to a supergiant star.

-8.73
A2I
9125K

The red dot in the diagram below shows where Deneb is situated in the Hertzsprung–Russell diagram.

HR Diagram
H-R diagram showing the position of Deneb. Attribution: Richard Powell / CC BY-SA

Deneb star system properties

Deneb is a visual double star which can be observed only with the help of very large telescopes. The table below shows key information about the Deneb double sysyem:

1.25
11.25
10
75.4 arcsec

Alternative designations of Deneb

Deneb
α Cygni
(alpha Cygni)
SAO49941
SAO49941