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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: 6:38  
clear_day Transit: 12:10  
SunsetSet: 17:43
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All Constellations » Perseus » 

ι Persei (iota Persei)

Altitude: 72.3°   Azimuth: 275.0°   Direction: West

ι Persei is a double hypergiant star in the constellation of Perseus.

ι Persei visual magnitude is 4.05. Because of its moderate brightness, ι 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 ι Persei is 1.263 arcsec per year in Right Ascension and -0.091 arcsec per year in Declination and the associated displacement for the next 100 years is represented with the red arrow.

Image of ι Persei (iota Persei) star
DSS2 image of ι Persei. The red arrow shows the motion of ι Persei during the next 100 years (2.11 arcmin in Right Ascension and -0.15 arcmin in declination);

Key facts about ι Persei


ι Persei (iota Persei) is above the horizon from Greenwich, United Kingdom edit_location_alt.

Altitude: 72.3°
Azimuth: 275.0°
Direction: West

Celestial coordinates and finder chart of ι Persei

ι 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 ι Persei are provided in the following table:

03h 09m 03s
+49° 36’ 47”

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

Finder chart ι Persei (iota Persei) star
Simplified finder chart for ι Persei (iota Persei).

Visibility of ι Persei from your location

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

ι Persei (iota Persei) is circumpolar and transits at 16:17 UTC (altitude: 88.1°)

Distance of ι Persei from the Sun and relative movement

ι Persei is distant 34.34 light years from the Sun and it is moving far from the Sun at the speed of 50 kilometers per second.

10.53 pc
34.34 ly
50 km/s
1.263 arcsec/year
-0.091 arcsec/year

Spectral properties of ι Persei

ι Persei belongs to spectral class G0 and has a luminosity class of V corresponding to a hypergiant star.


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

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

ι Persei star system properties

ι Persei 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 ι Persei double sysyem:

146.2 arcsec

Alternative designations of ι Persei

ι Persei
(iota Persei)