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🌎  Greenwich, United Kingdom [change]

77 Cygni

77 Cygni is a double hypergiant star in the constellation of Cygnus.

77 Cygni visual magnitude is 5.69. Because of its reltive faintness, 77 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 77 Cygni:

5.69
Hypergiant
77 Cygni is above the horizon from Greenwich, United Kingdom [change]. Altitude: 11°.

Celestial coordinates and finder chart of 77 Cygni

77 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 77 Cygni are provided in the following table:

21h 42m 22s
+41° 04’ 37”
88.84°
-8.96°
Cygnus

The simplified sky map below shows the position of 77 Cygni in the sky:

Finder chart 77 Cygni star
Simplified finder chart for 77 Cygni.

Visibility of 77 Cygni from your location

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

77 Cygni is circumpolar and transits at 02:42 UTC (altitude: 79.6°)

Digitized Sky Survey image of 77 Cygni

The image below is a photograph of 77 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 77 Cygni is 0.021 arcsec per year in Right Ascension and 0.003 arcsec per year in Declination and the associated displacement for the next 10000 years is represented with the red arrow.

Image of 77 Cygni star
DSS2 image of 77 Cygni. The red arrow shows the motion of 77 Cygni during the next 10000 years (3.50 arcmin in Right Ascension and 0.50 arcmin in declination);

Distance of 77 Cygni from the Sun and relative movement

77 Cygni is distant 372.15 light years from the Sun and it is moving towards the Sun at the speed of 25 kilometers per second.

114.16 pc
372.15 ly
-25 km/s
0.021 arcsec/year
0.003 arcsec/year

Spectral properties of 77 Cygni

77 Cygni belongs to spectral class A0 and has a luminosity class of V corresponding to a hypergiant star.

0.40
A0V
10002K

The red dot in the diagram below shows where 77 Cygni is situated in the Hertzsprung–Russell diagram.

HR Diagram
H-R diagram showing the position of 77 Cygni. Attribution: Richard Powell / CC BY-SA

77 Cygni star system properties

77 Cygni 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 77 Cygni double sysyem:

5.69
5.89
0.2
0.1 arcsec

Alternative designations of 77 Cygni

SAO51207
SAO51207