Your guide to the Solar System and the night sky
🌎 Location: Greenwich, United Kingdom [change]

δ Cephei (delta Cephei)

δ Cephei is a variable and multiple supergiant star in the constellation of Cepheus.

δ Cephei visual magnitude is 3.75. Because of its moderate brightness, δ Cephei 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 δ Cephei:

3.75
Supergiant
δ Cephei (delta Cephei) is above the horizon from Greenwich, United Kingdom [change]. Altitude: 77°.

Celestial coordinates and finder chart of δ Cephei

δ Cephei 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 δ Cephei are provided in the following table:

22h 29m 10s
+58° 24’ 55”
105.19°
0.53°
Cepheus

The simplified sky map below shows the position of δ Cephei in the sky:

Finder chart δ Cephei (delta Cephei) star
Simplified finder chart for δ Cephei (delta Cephei).

Visibility of δ Cephei from your location

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

δ Cephei (delta Cephei) is circumpolar and transits at 20:18 UTC (altitude: 83.1°)

Digitized Sky Survey image of δ Cephei

The image below is a photograph of δ Cephei 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 δ Cephei is 0.015 arcsec per year in Right Ascension and 0.001 arcsec per year in Declination and the associated displacement for the next 10000 years is represented with the red arrow.

Image of δ Cephei (delta Cephei) star
DSS2 image of δ Cephei. The red arrow shows the motion of δ Cephei during the next 10000 years (2.50 arcmin in Right Ascension and 0.17 arcmin in declination);

Distance of δ Cephei from the Sun and relative movement

δ Cephei is distant 981.93 light years from the Sun and it is moving towards the Sun at the speed of 15 kilometers per second.

301.20 pc
981.93 ly
-15 km/s
0.015 arcsec/year
0.001 arcsec/year

Spectral properties of δ Cephei

δ Cephei belongs to spectral class F5 and has a luminosity class of I corresponding to a supergiant star.

-3.64
F5I
5968K

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

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

δ Cephei star system properties

δ Cephei is a visual double star which can be observed with binoculars or small telescopes. The table below shows key information about the δ Cephei double sysyem:

3.75
6.15
2.4
40.8 arcsec

Alternative designations of δ Cephei

δ Cephei
(delta Cephei)
SAO34508
SAO34508