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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: 6:57  
clear_day Transit: 12:11  
SunsetSet: 17:27
sunny DaytimeWhat's Visible Now?
All Constellations » Leo » 

τ Leonis (tau Leonis)

Altitude: -34.8°   Azimuth: 346.0°   Direction: North-North-West

τ Leonis is a multiple giant star in the constellation of Leo.

τ Leonis visual magnitude is 4.95. Because of its moderate brightness, τ Leonis 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 proper motion of τ Leonis is 0.018 arcsec per year in Right Ascension and -0.012 arcsec per year in Declination and the associated displacement for the next 10000 years is represented with the red arrow.

Image of τ Leonis (tau Leonis) star
DSS2 image of τ Leonis. The red arrow shows the motion of τ Leonis during the next 10000 years (3.00 arcmin in Right Ascension and -2.00 arcmin in declination);

Key facts about τ Leonis


τ Leonis (tau Leonis) is below the horizon from Greenwich, United Kingdom edit_location_alt.

Altitude: -34.8°
Azimuth: 346.0°
Direction: North-North-West

Celestial coordinates and finder chart of τ Leonis

τ Leonis 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 τ Leonis are provided in the following table:

11h 27m 56s
+02° 51’ 21”

The simplified sky map below shows the position of τ Leonis in the sky:

Finder chart τ Leonis (tau Leonis) star
Simplified finder chart for τ Leonis (tau Leonis).

Visibility of τ Leonis 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 τ Leonis (tau Leonis) 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: 87.1°
Max altitude: 41.4°
Azimuth: 272.9°

Distance of τ Leonis from the Sun and relative movement

τ Leonis is distant 620.95 light years from the Sun and it is moving towards the Sun at the speed of 9 kilometers per second.

190.48 pc
620.95 ly
-9 km/s
0.018 arcsec/year
-0.012 arcsec/year

Spectral properties of τ Leonis

τ Leonis belongs to spectral class G7 and has a luminosity class of III corresponding to a giant star.


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

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

τ Leonis star system properties

τ Leonis is a visual double star which can be observed with binoculars or small telescopes. The table below shows key information about the τ Leonis double sysyem:

91.1 arcsec

Alternative designations of τ Leonis

τ Leonis
(tau Leonis)