Blue supergiant · Orion

Alnitak

Also known as: ζ Orionis (ζ Ori), HIP 26727

mag 1.7740 light-years

About

Alnitak (ζ Orionis) is a blue supergiant of magnitude 1.7 in Orion, about 740 light-years away.

Alnitak is in the constellation Orion.
Best evenings: around late January 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 78° N.
Star patterns: Orion’s Belt and Sword.

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.

EyesEasy, even from town. It looks blue-white.
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	Alnitak
Designation	ζ Orionis (ζ Ori)
Hipparcos number	HIP 26727
Type	Blue supergiant
Spectral type	O9.5Ib SB
Colour	Blue-whiteB−V colour index −0.20
Magnitude	1.7The smaller the number, the brighter.
Distance	740 light-yearsThe light you see left it around 1290.
Proper motion	0.005″ per year across the sky
Constellation	Orion
Right ascension (J2000)	05h 40m 45.5s
Declination (J2000)	−01° 56′ 33″