77 Cygni

Altitude: 50.8° Azimuth: 82.6° Direction: East

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:

Color of 77 Cygni ⬤

Magnitude of 77 Cygni 5.69

Class Hypergiant

VISIBILITY RIGHT NOW

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

Altitude: 50.8°
Azimuth: 82.6°
Direction: East

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:

Right Ascension J2000 21h 42m 22s

Declination J2000 +41° 04’ 37”

Galactic Longitude 88.84°

Galactic Latitude -8.96°

Constellation Cygnus

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

Simplified finder chart for 77 Cygni.

Visibility of 77 Cygni from your location

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

77 Cygni is circumpolar and transits at 16:45 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.

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.

Distance (parsec) 114.16 pc

Distance (light year) 372.15 ly

Heliocentric radial velocity -25 km/s

Proper Motion RA 0.021 arcsec/year

Proper Motion Dec 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.

Absolute magnitude 0.40

Spectral Type A0V

Color Index (B-V) 0.01

Temperature of 77 Cygni 10002K

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

Main star magnitude 5.69

Secondary star magnitude 5.89

Magnitude difference 0.2

Separation 0.1 arcsec

Alternative designations of 77 Cygni

Flamsteed designation 77 Cygni

Henry Draper Catalogue HD206644

SAO Catalogue SAO51207

Hipparcos Catalogue HIP107162

Durchmusterung Catalogue BD+40 4615

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In Evidence

Other stars in Cygnus