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public  Greenwich, UK Greenwich, UK  ⓘ
TimezoneEurope/London
Sunrise: 4:57 
Transit: 12:56 
Sunset: 20:56
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All Constellations » Perseus » 

τ Persei (tau Persei)

Above the horizon.  Circumpolar today
Alt: 14.35°   Az: 359.15°   Direction: North

τ Persei is a variable and multiple giant star of spectral class G4 in the constellation of Perseus.

τ Persei visual magnitude is 3.95. Because of its moderate brightness, τ Persei is easily visible to the naked eye from locations with dark skies, while it might be barely visible, or not visible at all, from light-polluted skies.

Image of τ Persei (tau Persei) star
DSS2 image of τ Persei. The red arrow shows the motion of τ Persei during the next 100000 years (0.00 arcmin in Right Ascension and -8.33 arcmin in declination);

Celestial Coordinates

Apparent

02h 56m 04s
+52° 51’ 52”
11h 54m 31s
14h 50m 35s

J2000

02h 54m 15s
+52° 45’ 45”

Galactic Coordinates

141.02°
-5.74°

Finder Chart

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Finder chart for τ Persei (tau Persei).

Magnitude, Color, Spectral Class

3.95
Giant

-0.46
G4III
5468K

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

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

Star System Properties

τ 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 τ Persei double sysyem:

3.95
12.55
8.6
51.7 arcsec

Distance, Radial Speed, Proper Motion

τ Persei is distant 247.91 light years from the Sun and it is moving far from the Sun at the speed of 2 kilometers per second.

76.05
247.91
2 km/s
-0.005"/y

Alternative Designations

τ Persei
(tau Persei)
SAO23685
SAO23685

Visibility from Your Location

τ Persei (tau Persei) is circumpolar and transits at 10:46 UTC (altitude: 88.6°)