Puppis

What is Puppis?

Constellations· Winter–spring evenings · southeast of Canis Major. The Stern of the old ship Argo. Its brightest star Naos is among the hottest stars visible to the naked eye, and open clusters like M46 and M47 are easy binocular targets. Follow the sky below Sirius in the Sky view to find it.

📍 Visible from where you are right now — computed in your browser

bearing · altitude · rise time · best time tonight

Puppis
Image: NowSky rendering (an illustration, not a photograph)· Wikipedia
Puppis star lines
Star lines — the stars used and how they connect (NowSky)

Where Puppis is in your sky right now: https://nowsky.org/solar/sky?sel=con:Puppis — location and time set automatically, no login.

Stars of the figure

StarMagnitude
Naos2.2

The 1 brightest of the 6 stars used in the figure (5 lines). Lower magnitude means brighter.

Deep-sky objects near this constellation

NGC 2477open clusterVY Canis MajorisstarScholz's StarstarDouble PulsarpulsarGum Nebulanebula

Constellation basics

SeasonFeb–Mar evenings, low south; northern half visible from Korea
Brightest starζ Puppis (Naos), mag 2.2
How to findbelow-left of Sirius, following the Milky Way south
Area rank20th of 88

Figures are representative approximations. Source: compiled from NASA and IAU public data.

Frequently asked

When can I see Puppis?
Feb–Mar evenings, low south; northern half visible from Korea.
How do I find Puppis?
below-left of Sirius, following the Milky Way south.
What is the brightest star in Puppis?
Naos, magnitude 2.2.
Where is Puppis in the sky right now?
Open the sky view for your location and time and it shows the position in the sky right now.

A distance measured from a light echo — RS Puppis

RS Puppis, a Cepheid variable in Puppis, is a bright star pulsating with a 41.4-day period and wrapped in a thick cloud of dust. Each time it brightens and fades, the light sweeps outward across the cloud in a light echo, and in 2010 and 2013 Hubble photographed the rings in sequence as they moved. Since the echo spreads at the speed of light, the angular size of the rings gives the distance.

Measured this way, RS Puppis lies 6,500 light-years away with an uncertainty of one percent, making it the Cepheid with the most precisely known distance. Cepheids form the first rung of the cosmic distance ladder, so the precision of this one star carries through to the accuracy of galaxy distances everywhere. In the constellation that is the stern of the Argo, light running across dust became the ruler itself.

The constellation in depth

Puppis, the Stern, is the largest of the three pieces into which Lacaille divided Argo Navis in the 1750s. In Greek myth Argo was the ship Jason and the Argonauts sailed in search of the Golden Fleece, later placed in the sky. Even after the split, the stars kept the Greek letters they had as part of the original ship.

Its brightest star, zeta Puppis or Naos, is a blue supergiant hotter than 40,000 K and hundreds of thousands of times more luminous than the Sun. Because the constellation lies on the Milky Way it is rich in open clusters: M46 has a planetary nebula superimposed on it, while neighbouring M47 is a loose sprinkling of bright stars.

The northern half rises above the southern horizon from Korea on February and March evenings. Drop your gaze down and left from Sirius and the Milky Way thickens with stars — that is Puppis. In the Sky view, try Seoul on a February night looking south, or choose a southern city to see the whole figure.

Related

Figures are representative approximations. Simulated positions use J2000 mean elements.