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A Complete Guide to the Solar System and the Night Sky
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public Observing fromLocation: Greenwich, United Kingdom edit_location_alt
SunriseRise: 6:44  
clear_day Transit: 12:10  
SunsetSet: 17:38
sunny DaytimeWhat's Visible Now?
All Constellations » Perseus » 

σ Persei (sigma Persei)

Altitude: 46.9°   Azimuth: 66.2°   Direction: East-North-East

σ Persei is a variable giant star in the constellation of Perseus.

σ Persei visual magnitude is 4.36. Because of its moderate brightness, σ Persei should be easily visible from locations with dark skies, while it can be barely visible, or not visible at all, from skies affected by light pollution.

The proper motion of σ Persei is 0.004 arcsec per year in Right Ascension and 0.02 arcsec per year in Declination and the associated displacement for the next 10000 years is represented with the red arrow.

Image of σ Persei (sigma Persei) star
DSS2 image of σ Persei. The red arrow shows the motion of σ Persei during the next 10000 years (0.67 arcmin in Right Ascension and 3.33 arcmin in declination);

Key facts about σ Persei


σ Persei (sigma Persei) is above the horizon from Greenwich, United Kingdom edit_location_alt.

Altitude: 46.9°
Azimuth: 66.2°
Direction: East-North-East

Celestial coordinates and finder chart of σ Persei

σ Persei 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 Persei are provided in the following table:

03h 30m 34s
+47° 59’ 43”

The simplified sky map below shows the position of σ Persei in the sky:

Finder chart σ Persei (sigma Persei) star
Simplified finder chart for σ Persei (sigma Persei).

Visibility of σ Persei from your location

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

σ Persei (sigma Persei) is circumpolar and transits at 16:50 UTC (altitude: 86.5°)

Distance of σ Persei from the Sun and relative movement

σ Persei is distant 353.20 light years from the Sun and it is moving far from the Sun at the speed of 16 kilometers per second.

108.34 pc
353.20 ly
16 km/s
0.004 arcsec/year
0.02 arcsec/year

Spectral properties of σ Persei

σ Persei belongs to spectral class K3 and has a luminosity class of III corresponding to a giant star.


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

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

Alternative designations of σ Persei

σ Persei
(sigma Persei)