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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: 7:44  
clear_day Transit: 11:48  
SunsetSet: 15:51 south
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All Constellations » Eridanus » 

τ9 Eridani (tau9 Eridani)

Altitude: -44.2°   Azimuth: 288.0°   Direction: West-North-West

τ9 Eridani is a variable main-sequence star in the constellation of Eridanus.

τ9 Eridani visual magnitude is 4.66. Because of its moderate brightness, τ9 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 τ9 Eridani:


τ9 Eridani (tau9 Eridani) is below the horizon from Greenwich, United Kingdom edit_location_alt.

Altitude: -44.2°
Azimuth: 288.0°
Direction: West-North-West

Celestial coordinates and finder chart of τ9 Eridani

τ9 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 τ9 Eridani are provided in the following table:

03h 59m 55s
-24° 00’ 59”

The simplified sky map below shows the position of τ9 Eridani in the sky:

Finder chart τ9 Eridani (tau9 Eridani) star
Simplified finder chart for τ9 Eridani (tau9 Eridani).

Visibility of τ9 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 τ9 Eridani (tau9 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: 114.0°
Max altitude: 14.5°
Azimuth: 246.0°

Digitized Sky Survey image of τ9 Eridani

The image below is a photograph of τ9 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 τ9 Eridani is 0.015 arcsec per year in Right Ascension and 0.015 arcsec per year in Declination and the associated displacement for the next 10000 years is represented with the red arrow.

Image of τ9 Eridani (tau9 Eridani) star
DSS2 image of τ9 Eridani. The red arrow shows the motion of τ9 Eridani during the next 10000 years (2.50 arcmin in Right Ascension and 2.50 arcmin in declination);

Distance of τ9 Eridani from the Sun and relative movement

τ9 Eridani is distant 330.96 light years from the Sun and it is moving far from the Sun at the speed of 24 kilometers per second.

101.52 pc
330.96 ly
24 km/s
0.015 arcsec/year
0.015 arcsec/year

Spectral properties of τ9 Eridani

τ9 Eridani belongs to spectral class B6 and has a luminosity class of V corresponding to a main-sequence star.


The red dot in the diagram below shows where τ9 Eridani is situated in the Hertzsprung–Russell diagram.

HR Diagram
H-R diagram showing the position of τ9 Eridani. Attribution: Richard Powell / CC BY-SA

Alternative designations of τ9 Eridani

τ9 Eridani
(tau9 Eridani)