σ Cygni (sigma Cygni)
σ Cygni is a variable supergiant star in the constellation of Cygnus.
σ Cygni visual magnitude is 4.23. Because of its moderate brightness, σ Cygni should be easily visible from locations with dark skyes, while it can be barely visible, or not visible at all, from skyes affected by light pollution.
The table below summarizes the key facts about σ Cygni:
Celestial coordinates and finder chart of σ Cygni
σ 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 σ Cygni are provided in the following table:
The simplified sky map below shows the position of σ Cygni in the sky:
Visibility of σ Cygni from your location
Location: Greenwich, United Kingdom [change]
Latitude: 51° 28’ 47” N
Longitude: 0° 00’ 00” E
Timezone: Europe/London
σ Cygni (sigma Cygni) is circumpolar and transits at 20:43 UTC (altitude: 77.9°)
Digitized Sky Survey image of σ Cygni
The image below is a photograph of σ 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 σ Cygni is 0.001 arcsec per year in Right Ascension and -0.003 arcsec per year in Declination and the associated displacement for the next 100000 years is represented with the red arrow.
Distance of σ Cygni from the Sun and relative movement
σ Cygni is distant 4,527.78 light years from the Sun and it is moving towards the Sun at the speed of 4 kilometers per second.
Spectral properties of σ Cygni
σ Cygni belongs to spectral class B9 and has a luminosity class of I corresponding to a supergiant star.
The red dot in the diagram below shows where σ Cygni is situated in the Hertzsprung–Russell diagram.
