Yellow-white giant · Sagittarius

Arkab Posterior

Also known as: β² Sagittarii (β² Sgr), HIP 95294

mag 4.3130 light-years

About

Arkab Posterior (β² Sagittarii) is a yellow-white giant of magnitude 4.3 in Sagittarius, about 130 light-years away.

Arkab Posterior 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 35° 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	Arkab Posterior
Designation	β² Sagittarii (β² Sgr)
Hipparcos number	HIP 95294
Type	Yellow-white giant
Spectral type	F2III
Colour	Yellowish whiteB−V colour index 0.35
Magnitude	4.3The smaller the number, the brighter.
Distance	130 light-yearsThe light you see left it around 1890.
Proper motion	0.11″ per year across the sky
Constellation	Sagittarius
Right ascension (J2000)	19h 23m 13.1s
Declination (J2000)	−44° 47′ 59″