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public Observing fromLocation: Greenwich, United Kingdom edit_location_alt
north SunriseRise: 7:04  
clear_day Transit: 12:47  
SunsetSet: 18:30 south
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All Constellations » Gemini » 

τ Geminorum (tau Geminorum)

Altitude: 51.3°   Azimuth: 254.0°   Direction: West-South-West

τ Geminorum is a variable and multiple giant star in the constellation of Gemini.

τ Geminorum visual magnitude is 4.41. Because of its moderate brightness, τ Geminorum 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 τ Geminorum:


τ Geminorum (tau Geminorum) is above the horizon from Greenwich, United Kingdom edit_location_alt.

Altitude: 51.3°
Azimuth: 254.0°
Direction: West-South-West

Celestial coordinates and finder chart of τ Geminorum

τ Geminorum 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 τ Geminorum are provided in the following table:

07h 11m 08s
+30° 14’ 43”

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

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

Visibility of τ Geminorum 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 Geminorum (tau Geminorum) 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: 59.8°
Max altitude: 68.8°
Azimuth: 300.2°

Digitized Sky Survey image of τ Geminorum

The image below is a photograph of τ Geminorum 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 τ Geminorum is -0.03 arcsec per year in Right Ascension and -0.045 arcsec per year in Declination and the associated displacement for the next 10000 years is represented with the red arrow.

Image of τ Geminorum (tau Geminorum) star
DSS2 image of τ Geminorum. The red arrow shows the motion of τ Geminorum during the next 10000 years (-5.00 arcmin in Right Ascension and -7.50 arcmin in declination);

Distance of τ Geminorum from the Sun and relative movement

τ Geminorum is distant 301.57 light years from the Sun and it is moving far from the Sun at the speed of 22 kilometers per second.

92.51 pc
301.57 ly
22 km/s
-0.03 arcsec/year
-0.045 arcsec/year

Spectral properties of τ Geminorum

τ Geminorum belongs to spectral class K2 and has a luminosity class of III corresponding to a giant star.


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

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

τ Geminorum star system properties

τ Geminorum 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 Geminorum double sysyem:

1.9 arcsec

Alternative designations of τ Geminorum

τ Geminorum
(tau Geminorum)
46 Geminorum