All Constellations » Sagittarius »

Rukbat - α Sagittarii (alpha Sagittarii)

Rukbat, also designated as α Sagittarii (alpha Sagittarii), is a main-sequence star in the constellation of Sagittarius.

Rukbat visual magnitude is 3.97. Because of its moderate brightness, Rukbat 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 Rukbat:

Color of Rukbat ⬤

Magnitude of Rukbat 3.97

Class Main-sequence

VISIBILITY RIGHT NOW Rukbat - α Sagittarii (alpha Sagittarii) is below the horizon from Greenwich, United Kingdom edit_location_alt.

Celestial coordinates and finder chart of Rukbat

Rukbat is situated south of the celestial equator, as such, it is more easily visible from the southern hemisphere. Celestial coordinates for the J2000 equinox as well as galactic coordinates of Rukbat are provided in the following table:

Right Ascension J2000 19h 23m 53s

Declination J2000 -40° 36’ 57”

Galactic Longitude 357.71°

Galactic Latitude -23.09°

Constellation Sagittarius

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

Finder chart Rukbat - α Sagittarii (alpha Sagittarii) star

Simplified finder chart for Rukbat - α Sagittarii (alpha Sagittarii).

Visibility of Rukbat from your location

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

Rukbat - α Sagittarii (alpha Sagittarii) is currently not visible from Greenwich, United Kingdom edit_location_alt

Digitized Sky Survey image of Rukbat

The image below is a photograph of Rukbat 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 Rukbat is 0.03 arcsec per year in Right Ascension and -0.123 arcsec per year in Declination and the associated displacement for the next 1000 years is represented with the red arrow.

Image of Rukbat - α Sagittarii (alpha Sagittarii) star

DSS2 image of Rukbat. The red arrow shows the motion of Rukbat during the next 1000 years (0.50 arcmin in Right Ascension and -2.05 arcmin in declination);

Distance of Rukbat from the Sun and relative movement

Rukbat is distant 169.79 light years from the Sun and it is moving towards the Sun at the speed of 1 kilometers per second.

Distance (parsec) 52.08 pc

Distance (light year) 169.79 ly

Heliocentric radial velocity -1 km/s

Proper Motion RA 0.03 arcsec/year

Proper Motion Dec -0.123 arcsec/year

Spectral properties of Rukbat

Rukbat belongs to spectral class B8 and has a luminosity class of V corresponding to a main-sequence star.

Absolute magnitude 0.39

Spectral Type B8V

Color Index (B-V) -0.1

Temperature of Rukbat 11573K

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

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

Alternative designations of Rukbat

Proper Name Rukbat

Bayer designation α Sagittarii
(alpha Sagittarii)

Henry Draper Catalogue HD181869

SAO Catalogue SAO229659

Hipparcos Catalogue HIP95347

Durchmusterung Catalogue CD-4013245

FK5 Catalogue 728

In Evidence

Other stars in Sagittarius