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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: 7:54  
clear_day Transit: 11:51  
SunsetSet: 15:49 south
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All Constellations » Gemini » 

81 Geminorum

Altitude: -18.0°   Azimuth: 19.3°   Direction: North-North-East

81 Geminorum is a giant star in the constellation of Gemini.

81 Geminorum visual magnitude is 4.88. Because of its moderate brightness, 81 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 81 Geminorum:


81 Geminorum is below the horizon from Greenwich, United Kingdom edit_location_alt.

Altitude: -18.0°
Azimuth: 19.3°
Direction: North-North-East

Celestial coordinates and finder chart of 81 Geminorum

81 Geminorum 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 81 Geminorum are provided in the following table:

07h 46m 07s
+18° 30’ 36”

The simplified sky map below shows the position of 81 Geminorum in the sky:

Finder chart 81 Geminorum star
Simplified finder chart for 81 Geminorum.

Visibility of 81 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 81 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: 71.5°
Max altitude: 57.0°
Azimuth: 288.5°

Digitized Sky Survey image of 81 Geminorum

The image below is a photograph of 81 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 81 Geminorum is -0.076 arcsec per year in Right Ascension and -0.058 arcsec per year in Declination and the associated displacement for the next 10000 years is represented with the red arrow.

Image of 81 Geminorum star
DSS2 image of 81 Geminorum. The red arrow shows the motion of 81 Geminorum during the next 10000 years (-12.67 arcmin in Right Ascension and -9.67 arcmin in declination);

Distance of 81 Geminorum from the Sun and relative movement

81 Geminorum is distant 341.36 light years from the Sun and it is moving far from the Sun at the speed of 81 kilometers per second.

104.71 pc
341.36 ly
81 km/s
-0.076 arcsec/year
-0.058 arcsec/year

Spectral properties of 81 Geminorum

81 Geminorum belongs to spectral class K4 and has a luminosity class of III corresponding to a giant star.


The red dot in the diagram below shows where 81 Geminorum is situated in the Hertzsprung–Russell diagram.

HR Diagram
H-R diagram showing the position of 81 Geminorum. Attribution: Richard Powell / CC BY-SA

Alternative designations of 81 Geminorum

81 Geminorum