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A Complete Guide to the Solar System and the Night Sky
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public Observing fromLocation: Greenwich, United Kingdom edit_location_alt
north SunriseRise: 7:52  
clear_day Transit: 11:51  
SunsetSet: 15:49 south
wb_twilight Nautical TwilightWhat's Visible Now?
All Constellations » Cygnus » 

40 Cygni

Altitude: 13.9°   Azimuth: 44.1°   Direction: North-East

40 Cygni is a main-sequence star in the constellation of Cygnus.

40 Cygni visual magnitude is 5.62. Because of its reltive faintness, 40 Cygni should be visible only from locations with dark skyes, while it is not visible at all from skyes affected by light pollution.

The table below summarizes the key facts about 40 Cygni:


40 Cygni is above the horizon from Greenwich, United Kingdom edit_location_alt.

Altitude: 13.9°
Azimuth: 44.1°
Direction: North-East

Celestial coordinates and finder chart of 40 Cygni

40 Cygni 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 40 Cygni are provided in the following table:

20h 27m 34s
+38° 26’ 25”

The simplified sky map below shows the position of 40 Cygni in the sky:

Finder chart 40 Cygni star
Simplified finder chart for 40 Cygni.

Visibility of 40 Cygni from your location

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

Today's 40 Cygni rise, transit and set times from Greenwich, United Kingdom edit_location_alt are the following (all times relative to the local timezone Europe/London):

Azimuth: 51.6°
Max altitude: 77.0°
Azimuth: 308.4°

Digitized Sky Survey image of 40 Cygni

The image below is a photograph of 40 Cygni 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 40 Cygni is -0.023 arcsec per year in Right Ascension and -0.07 arcsec per year in Declination and the associated displacement for the next 10000 years is represented with the red arrow.

Image of 40 Cygni star
DSS2 image of 40 Cygni. The red arrow shows the motion of 40 Cygni during the next 10000 years (-3.83 arcmin in Right Ascension and -11.67 arcmin in declination);

Distance of 40 Cygni from the Sun and relative movement

40 Cygni is distant 270.09 light years from the Sun

82.85 pc
270.09 ly
-0.023 arcsec/year
-0.07 arcsec/year

Spectral properties of 40 Cygni

40 Cygni belongs to spectral class A3 and has a luminosity class of V corresponding to a main-sequence star.


The red dot in the diagram below shows where 40 Cygni is situated in the Hertzsprung–Russell diagram.

HR Diagram
H-R diagram showing the position of 40 Cygni. Attribution: Richard Powell / CC BY-SA

Alternative designations of 40 Cygni