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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: 7:47  
clear_day Transit: 11:49  
SunsetSet: 15:50 south
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All Constellations » Scorpius » 

Acrab - β1 Scorpii (beta1 Scorpii)

Altitude: -56.5°   Azimuth: 335.9°   Direction: North-North-West

Acrab, also designated as β1 Scorpii (beta1 Scorpii), is a variable and multiple main-sequence star in the constellation of Scorpius.

Acrab visual magnitude is 2.62. Thanks to its high brightness, Acrab 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 Acrab:


Acrab - β1 Scorpii (beta1 Scorpii) is below the horizon from Greenwich, United Kingdom edit_location_alt.

Altitude: -56.5°
Azimuth: 335.9°
Direction: North-North-West

Celestial coordinates and finder chart of Acrab

Acrab 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 Acrab are provided in the following table:

16h 05m 26s
-19° 48’ 20”

The simplified sky map below shows the position of Acrab in the sky:

Finder chart Acrab - β1 Scorpii (beta1 Scorpii) star
Simplified finder chart for Acrab - β1 Scorpii (beta1 Scorpii).

Visibility of Acrab 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 Acrab - β1 Scorpii (beta1 Scorpii) 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: 109.8°
Max altitude: 18.7°
Azimuth: 250.2°

Digitized Sky Survey image of Acrab

The image below is a photograph of Acrab 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 Acrab is -0.006 arcsec per year in Right Ascension and -0.019 arcsec per year in Declination and the associated displacement for the next 10000 years is represented with the red arrow.

Image of Acrab - β1 Scorpii (beta1 Scorpii) star
DSS2 image of Acrab. The red arrow shows the motion of Acrab during the next 10000 years (-1.00 arcmin in Right Ascension and -3.17 arcmin in declination);

Distance of Acrab from the Sun and relative movement

Acrab is distant 530.08 light years from the Sun and it is moving towards the Sun at the speed of 1 kilometers per second.

162.60 pc
530.08 ly
-1 km/s
-0.006 arcsec/year
-0.019 arcsec/year

Spectral properties of Acrab

Acrab belongs to spectral class B1 and has a luminosity class of V corresponding to a main-sequence star.


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

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

Acrab star system properties

Acrab 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 Acrab double sysyem:

0 arcsec

Alternative designations of Acrab

β1 Scorpii
(beta1 Scorpii)