55 Cygni

Above the horizon. Circumpolar today

Alt: 52.24° Az: 285.72° Direction: South

55 Cygni is a variable and double supergiant star of spectral class B3 in the constellation of Cygnus.

55 Cygni visual magnitude is 4.84. Because of its moderate brightness, 55 Cygni is easily visible to the naked eye from locations with dark skies, while it might be barely visible, or not visible at all, from light-polluted skies.

DSS2 image of 55 Cygni. The red arrow shows the motion of 55 Cygni during the next 100000 years (6.67 arcmin in Right Ascension and 0.00 arcmin in declination);

Celestial Coordinates

Apparent

Right Ascension 20h 49m 48s

Declination +46° 12’ 34”

Hour Angle 03h 53m 35s

Sidereal Time 00h 43m 24s

J2000

Right Ascension 20h 48m 56s

Declination +46° 06’ 51”

Galactic Coordinates

Galactic Longitude 85.75°

Galactic Latitude 1.49°

Finder Chart

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Finder chart for 55 Cygni.

Magnitude, Color, Spectral Class

Color ⬤

Magnitude 4.84

Class Supergiant

Absolute magnitude -4.35

Spectral Type B3I

Color Index (B-V) 0.41

Temperature 6827K

The red dot in the diagram below shows where 55 Cygni is situated in the Hertzsprung–Russell diagram.

H-R diagram showing the position of 55 Cygni. Attribution: Richard Powell / CC BY-SA

Star System Properties

55 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 55 Cygni double sysyem:

Main star magnitude 4.84

Secondary star magnitude 11.14

Magnitude difference 6.3

Separation 21.3 arcsec

Distance, Radial Speed, Proper Motion

55 Cygni is distant 2,248.28 light years from the Sun and it is moving towards the Sun at the speed of 7 kilometers per second.

Distance (parsec) 689.66

Distance (light year) 2,248.28

Radial Speed -7 km/s

Proper Motion RA 0.004 arcsec/y

Alternative Designations

Flamsteed designation 55 Cygni

Henry Draper Catalogue HD198478

SAO Catalogue SAO50099

Hipparcos Catalogue HIP102724

Durchmusterung Catalogue BD+45 3291

General Catalogue of Variable Stars V1661 Cyg

Aitken Double Star Catalogue ADS14337

Visibility from Your Location

55 Cygni is circumpolar and transits at 02:43 UTC (altitude: 84.7°)

Set Location

Other stars in Cygnus