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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
north SunriseRise: 7:47  
clear_day Transit: 11:49  
SunsetSet: 15:50 south
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All Constellations » Eridanus » 

τ3 Eridani (tau3 Eridani)

Altitude: -27.7°   Azimuth: 266.1°   Direction: West

τ3 Eridani is a sub-giant star in the constellation of Eridanus.

τ3 Eridani visual magnitude is 4.09. Because of its moderate brightness, τ3 Eridani 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 τ3 Eridani:


τ3 Eridani (tau3 Eridani) is below the horizon from Greenwich, United Kingdom edit_location_alt.

Altitude: -27.7°
Azimuth: 266.1°
Direction: West

Celestial coordinates and finder chart of τ3 Eridani

τ3 Eridani is situated close to the celestial equator, as such, it is at least partly visible from both hemispheres in certain times of the year. Celestial coordinates for the J2000 equinox as well as galactic coordinates of τ3 Eridani are provided in the following table:

03h 02m 23s
-23° 37’ 27”

The simplified sky map below shows the position of τ3 Eridani in the sky:

Finder chart τ3 Eridani (tau3 Eridani) star
Simplified finder chart for τ3 Eridani (tau3 Eridani).

Visibility of τ3 Eridani from your location

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

Today's τ3 Eridani (tau3 Eridani) rise, transit and set times from Greenwich, United Kingdom edit_location_alt are the following (all times relative to the local timezone Europe/London):

Azimuth: 113.6°
Max altitude: 14.9°
Azimuth: 246.4°

Digitized Sky Survey image of τ3 Eridani

The image below is a photograph of τ3 Eridani 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 τ3 Eridani is -0.145 arcsec per year in Right Ascension and -0.054 arcsec per year in Declination and the associated displacement for the next 1000 years is represented with the red arrow.

Image of τ3 Eridani (tau3 Eridani) star
DSS2 image of τ3 Eridani. The red arrow shows the motion of τ3 Eridani during the next 1000 years (-2.42 arcmin in Right Ascension and -0.90 arcmin in declination);

Distance of τ3 Eridani from the Sun and relative movement

τ3 Eridani is distant 86.13 light years from the Sun and it is moving towards the Sun at the speed of 10 kilometers per second.

26.42 pc
86.13 ly
-10 km/s
-0.145 arcsec/year
-0.054 arcsec/year

Spectral properties of τ3 Eridani

τ3 Eridani belongs to spectral class A4 and has a luminosity class of IV corresponding to a sub-giant star.


The red dot in the diagram below shows where τ3 Eridani is situated in the Hertzsprung–Russell diagram.

HR Diagram
H-R diagram showing the position of τ3 Eridani. Attribution: Richard Powell / CC BY-SA

Alternative designations of τ3 Eridani

τ3 Eridani
(tau3 Eridani)