Your Guide to the Solar System and the Night Sky
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public Observing fromLocation: Greenwich, United Kingdom edit_location_alt
north SunriseRise: 4:50  
clear_day Transit: 12:56  
SunsetSet: 21:03 south
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All Constellations » Lacerta » 

α Lacertae (alpha Lacertae)

α Lacertae is a double main-sequence star in the constellation of Lacerta.

α Lacertae visual magnitude is 3.77. Because of its moderate brightness, α Lacertae 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 α Lacertae:

α Lacertae (alpha Lacertae) is above the horizon from Greenwich, United Kingdom edit_location_alt. Altitude: 37°.

Celestial coordinates and finder chart of α Lacertae

α Lacertae 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 Lacertae are provided in the following table:

22h 31m 17s
+50° 16’ 56”

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

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

Visibility of α Lacertae from your location

Location: Greenwich, United Kingdom edit_location_alt
Latitude: 51° 28’ 47” N
Longitude: 0° 00’ 00” E
Timezone: Europe/London

α Lacertae (alpha Lacertae) is circumpolar and transits at 05:57 UTC (altitude: 88.8°)

Digitized Sky Survey image of α Lacertae

The image below is a photograph of α Lacertae 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 Lacertae is 0.138 arcsec per year in Right Ascension and 0.019 arcsec per year in Declination and the associated displacement for the next 1000 years is represented with the red arrow.

Image of α Lacertae (alpha Lacertae) star
DSS2 image of α Lacertae. The red arrow shows the motion of α Lacertae during the next 1000 years (2.30 arcmin in Right Ascension and 0.32 arcmin in declination);

Distance of α Lacertae from the Sun and relative movement

α Lacertae is distant 102.32 light years from the Sun and it is moving towards the Sun at the speed of 4 kilometers per second.

31.39 pc
102.32 ly
-4 km/s
0.138 arcsec/year
0.019 arcsec/year

Spectral properties of α Lacertae

α Lacertae belongs to spectral class A1 and has a luminosity class of V corresponding to a main-sequence star.


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

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

α Lacertae star system properties

α Lacertae 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 α Lacertae double sysyem:

36.3 arcsec

Alternative designations of α Lacertae

α Lacertae
(alpha Lacertae)