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public Observing fromLocation: Greenwich, United Kingdom edit_location_alt
north SunriseRise: 7:02  
clear_day Transit: 12:47  
SunsetSet: 18:32 south
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All Constellations » Gemini » 

α Geminorum (alpha Geminorum)

Altitude: 63.6°   Azimuth: 231.3°   Direction: South-West

α Geminorum is a multiple main-sequence star in the constellation of Gemini.

α Geminorum visual magnitude is 2.88. Thanks to its high brightness, α Geminorum is clearly visible when observed from locations with dark skyes, and should be also quite easily visible from light polluted areas.

The table below summarizes the key facts about α Geminorum:


α Geminorum (alpha Geminorum) is above the horizon from Greenwich, United Kingdom edit_location_alt.

Altitude: 63.6°
Azimuth: 231.3°
Direction: South-West

Celestial coordinates and finder chart of α Geminorum

α 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 α Geminorum are provided in the following table:

07h 34m 36s
+31° 53’ 18”

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

Finder chart α Geminorum (alpha Geminorum) star
Simplified finder chart for α Geminorum (alpha Geminorum).

Visibility of α 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 α Geminorum (alpha 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: 58.1°
Max altitude: 70.4°
Azimuth: 301.9°

Digitized Sky Survey image of α Geminorum

The image below is a photograph of α 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 α Geminorum is -0.172 arcsec per year in Right Ascension and -0.099 arcsec per year in Declination and the associated displacement for the next 1000 years is represented with the red arrow.

Image of α Geminorum (alpha Geminorum) star
DSS2 image of α Geminorum. The red arrow shows the motion of α Geminorum during the next 1000 years (-2.87 arcmin in Right Ascension and -1.65 arcmin in declination);

Distance of α Geminorum from the Sun and relative movement

α Geminorum is distant 51.53 light years from the Sun and it is moving towards the Sun at the speed of 1 kilometers per second.

15.81 pc
51.53 ly
-1 km/s
-0.172 arcsec/year
-0.099 arcsec/year

Spectral properties of α Geminorum

α Geminorum belongs to spectral class A2 and has a luminosity class of V corresponding to a main-sequence star.


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

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

α Geminorum star system properties

α Geminorum is a visual double star which can be observed with the help of medium or large telescopes. The table below shows key information about the α Geminorum double sysyem:

2 arcsec

Alternative designations of α Geminorum

α Geminorum
(alpha Geminorum)
66 Geminorum
Gl 278 B