Blue-white main-sequence star · Eridanus

Achernar

Also known as: α Eridani (α Eri), HIP 7588

mag 0.5140 light-years

About

Achernar (α Eridani) is a blue-white main-sequence star of magnitude 0.5 in Eridanus, about 140 light-years away.

Achernar is in the constellation Eridanus.
Best evenings: around late November 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 23° 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.

EyesA first-magnitude star, obvious even from a city. It looks blue-white.
Binoculars (10×50)Dazzling, with its colour stronger than to the eye.
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	Achernar
Designation	α Eridani (α Eri)
Hipparcos number	HIP 7588
Type	Blue-white main-sequence star
Spectral type	B3Vp
Colour	Blue-whiteB−V colour index −0.16
Magnitude	0.5The smaller the number, the brighter.
Distance	140 light-yearsThe light you see left it around 1890.
Proper motion	0.097″ per year across the sky
Constellation	Eridanus
Right ascension (J2000)	01h 37m 42.8s
Declination (J2000)	−57° 14′ 12″

Star data: HYG Database by David Nash, CC BY-SA 4.0. All data sources →