SkyRef / Stars

Rukbat

α Sgr. Magnitude 3.97, white. Visible to the naked eye from a reasonably dark site.

The numbers

Designationα Sgr
Magnitude3.97
Colourwhite
Right ascension19.398h
Declination-40.62°
B−V index-0.10
CatalogueHR 7348

What you are looking at

Astronomers call it α Sgr — the Bayer designation, which reads as a Greek letter ranking its brightness within its constellation. Rukbat is the name people actually use.

Rukbat shines at magnitude 3.97, making it visible to the naked eye from a reasonably dark site. Its B−V colour index of -0.10 makes it white to the eye, corresponding to a surface temperature of around 8,000 K.

It sits at right ascension 19.40 hours and declination -40.6°. It lies south of the celestial equator and sits low for northern observers, better the further south you go.

Find it tonight

SkyRef shows exactly where Rukbat is from your location right now — altitude, compass direction, and rise and set times.

Open the live sky map →

Other named stars

SiriusCanopusArcturusRigil KentaurusVegaCapellaRigelProcyonAchernarBetelgeuseHadarAltairAldebaranAntaresSpicaPolluxFomalhautMimosaDenebAcruxRegulusAdharaShaulaBellatrixElnathMiaplacidusAlnilamAliothMirfakDubheKaus AustralisAlkaidMenkalinanAlhenaCastorAlphard