Blue-white main-sequence star · Sagittarius

Rukbat

Also known as: α Sagittarii (α Sgr), HIP 95347

mag 4.0180 light-years

About

Rukbat (α Sagittarii) is a blue-white main-sequence star of magnitude 4.0 in Sagittarius, about 180 light-years away.

Rukbat is in the constellation Sagittarius.
Best evenings: around late August it is highest at about 9 pm (10 pm in summer time); a month earlier, two hours later.
Where on Earth: it is seen well, at least 10° up, from south of 39° N.

When it rises and sets tonight, how high it climbs and how much the Moon gets in the way are worked out in your browser for your place.

EyesVisible from the suburbs on a clear night, but lost in bright city skies.
Binoculars (10×50)A sharp point; binoculars bring out its colour and the fainter stars around it.
Telescope (6–8 inch)Still a point of light at any magnification — stars are too far away to show a disc. Low in the sky, bright stars twinkle and flash colours.

Stars look the same in any instrument: brighter and sharper, but never bigger.

Proper name	Rukbat
Designation	α Sagittarii (α Sgr)
Hipparcos number	HIP 95347
Type	Blue-white main-sequence star
Spectral type	B8V
Colour	WhiteB−V colour index −0.10
Magnitude	4.0The smaller the number, the brighter.
Distance	180 light-yearsThe light you see left it around 1840.
Proper motion	0.13″ per year across the sky
Constellation	Sagittarius
Right ascension (J2000)	19h 23m 53.2s
Declination (J2000)	−40° 36′ 57″