Sadr - γ Cygni (gamma Cygni)

Altitude: 56.5° Azimuth: 269.0° Direction: West

Sadr, also designated as γ Cygni (gamma Cygni), is a variable and multiple supergiant star in the constellation of Cygnus.

Sadr visual magnitude is 2.2, making it the 64th brightest star in the sky. Thanks to its high brightness, Sadr 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 Sadr:

Color of Sadr ⬤

Magnitude of Sadr 2.2

Class Supergiant

VISIBILITY RIGHT NOW

Sadr - γ Cygni (gamma Cygni) is above the horizon from Greenwich, United Kingdom edit_location_alt.

Altitude: 56.5°
Azimuth: 269.0°
Direction: West

Celestial coordinates and finder chart of Sadr

Sadr 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 Sadr are provided in the following table:

Right Ascension J2000 20h 22m 13s

Declination J2000 +40° 15’ 24”

Galactic Longitude 78.15°

Galactic Latitude 1.87°

Constellation Cygnus

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

Finder chart Sadr - γ Cygni (gamma Cygni) star

Simplified finder chart for Sadr - γ Cygni (gamma Cygni).

Visibility of Sadr from your location

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

Sadr - γ Cygni (gamma Cygni) is circumpolar and transits at 20:04 UTC (altitude: 78.8°)

Digitized Sky Survey image of Sadr

The image below is a photograph of Sadr 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 Sadr is 0.004 arcsec per year in Right Ascension and 0 arcsec per year in Declination and the associated displacement for the next 100000 years is represented with the red arrow.

Image of Sadr - γ Cygni (gamma Cygni) star

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

Distance of Sadr from the Sun and relative movement

Sadr is distant 1,523.36 light years from the Sun and it is moving towards the Sun at the speed of 8 kilometers per second.

Distance (parsec) 467.29 pc

Distance (light year) 1,523.36 ly

Heliocentric radial velocity -8 km/s

Proper Motion RA 0.004 arcsec/year

Spectral properties of Sadr

Sadr belongs to spectral class F8 and has a luminosity class of I corresponding to a supergiant star.

Absolute magnitude -6.15

Spectral Type F8I

Color Index (B-V) 0.68

Temperature of Sadr 5671K

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

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

Sadr star system properties

Sadr 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 Sadr double sysyem:

Main star magnitude 2.2

Secondary star magnitude 10.7

Magnitude difference 8.5

Separation 141.2 arcsec

Alternative designations of Sadr

Proper Name Sadr

Bayer designation γ Cygni
(gamma Cygni)

Flamsteed designation 37 Cygni

Henry Draper Catalogue HD194093

SAO Catalogue SAO49528

Hipparcos Catalogue HIP100453

Durchmusterung Catalogue BD+39 4159

FK5 Catalogue 765

General Catalogue of Variable Stars 13048

Aitken Double Star Catalogue ADS13765

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