Blue supergiant · Puppis

Naos

Also known as: ζ Puppis (ζ Pup), HIP 39429

mag 2.21,100 light-years

About

Naos (ζ Puppis) is a blue supergiant of magnitude 2.2 in Puppis, about 1,100 light-years away.

Naos is in the constellation Puppis.
Best evenings: around early March 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 40° 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.

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	Naos
Designation	ζ Puppis (ζ Pup)
Hipparcos number	HIP 39429
Type	Blue supergiant
Spectral type	O5IAf
Colour	Blue-whiteB−V colour index −0.27
Magnitude	2.2The smaller the number, the brighter.
Distance	1,100 light-yearsThe light you see left it around AD 900. Distances this large are uncertain by 10% or more.
Proper motion	0.035″ per year across the sky
Constellation	Puppis
Right ascension (J2000)	08h 03m 35.1s
Declination (J2000)	−40° 00′ 11″