Puppis is a southern constellation, sandwiched between the two brightest stars in the sky, Sirius above and Canopus below, and not visible in its entirety above 35 degrees north latitude. It is the Latin name for the stern of a ship, which led to the English name of poop deck. It was once part of a much larger constellation, Argo Navis, which represented the stern section of the Argos, the legendary ship that transported Jason and the Argonauts on their quest to capture the Golden Fleece. The 1687 depiction of Argo Navis above by Hevelius is reversed, as many older star charts were, as if looking down from space at the outside of a shell of stars that surrounded Earth, as the ancients originally believed they did.
In 1751, during his famous expedition to South Africa to chart the southern skies, French astronomer Nicolas Lacaille decided the ancient constellation of Argo Navis was just too large and unwieldy. There were too many stars, and too many other, mysterious objects. The area needed to be divided into smaller, more manageable constellations. But the Argo Navis was such a majestic, traditional image it couldn't simply be scrapped and replaced by new constellations. So Lacaille compromised, and left the ancient image in the sky, with all its grand mythological romance, and simply divided the figure into three parts: Puppis, the poop deck, Vela, the sail, and Carina, the keel.
Lacaille did not, however, tamper with the original Bayer Designations (Greek letter hierarchy according to brightness) of the stars in Argo Navis. This means that each of the new constellations does not necessarily have its own alpha, beta, gamma star etc., but uses the original designations assigned to the entire Argo Navis. I have taken the liberty of tracing the new constellations over the magnificent artwork of Johann Bayer's 1603 Uranometria below, to help show their ancient origins.
At a magnitude of 2.21, the brightest star in the constellation is named Naos, from the Greek word for ship. It is a 06III blue giant, with a blistering surface temperature of 40,000 degrees C., making it one of the hottest stars known. Fortunately, all that heat is safely over 1,000 light years away.
At the top of the poop deck is the star named Azmidiske, from the Greek word for the Aplustre, a large, ornamental overhang which protected the stern of the ship. The name was once associated with the star Turais, down by the keel of the ship in the constellation Carina, before it was moved up to the poop deck where it belonged. It is a G3I yellow supergiant. Despite its large size. Azmidiske is only the seventh brightest star in Puppis, with a magnitude of 3.34, due to its relatively low surface temperature of 4,800 degrees K, and its distance of over 1000 light years. Recently it was discovered to have a dim, 13th magnitude companion, making it a binary system.
To date, seven stars in Puppis have been found to support planetary systems. All the planets discovered so far have been gas giants, and their stars are all too dim to be seen with the naked eye, except one. With a magnitude of 4.45, star HD 60532 can be easily seen up in the northern section of the constellation. It is a F6V yellow main sequence star, with at least two gas giants in orbit around it. The system is 84 light years from Earth. For more information on these and other extrasolar planets, visit NASA's New Worlds Atlas, and The Open Exoplanets Catalogue.
Puppis contains three Messier objects, all open star clusters inside the Milky Way. The first of these is M46 (NGC 2437), a grouping of about 500 stars, at a distance of 5,400 light years and a collective magnitude of 6.1. Directly in front of the cluster in the same line of sight, about 3,000 light years away, is the planetary nebula NGC 2438, a vast cloud of ionised gas cast off by a dying star at its centre.
The open cluster M47, (NGC 2422), is at a distance of 1,600 light years, and contains about 50 stars, with a collective magnitude of 4.4. In the image below M46 and NGC 2438 are on the left with the star cluster M47 on the right.
In this close up image of NGC 2438, the nebula lined up with M46, the central dying star can be seen as a tiny, dim, blue dot inside the nebula. The bright white stars around it are far in the background. The nebula itself has a magnitude of 10.8.
The third Messier object in Puppis is M93 (NGC 2447), another open star cluster, consisting of about 80 stars, about 3,600 light years away with a magnitude of 6.2.
NGC 2451 and NGC 2477 are two more open star clusters very different from each other, that can be seen together in the same field of view. In the ESO image below, NGC 2477, in the lower left of the image, is 3,600 light years away, and consists of about 300 stars, making it look almost like a globular cluster, but without the bright, dense core. It has a magnitude of 5.8.
NGC 2451 is in the upper right of the image, and actually consists of two separate clusters very far apart, but in the same line of sight. The nearer group, NGC 2451A, is about 670 light years away, and contains about 50 stars. NGC 2451B is about 1,200 light years away, and contains about 60 stars.
NGC 2440 is another planetary nebula created by a dying star. With a magnitude of 11.5, it is about 4,000 light years away. The dying white dwarf in the centre of the nebula is one of the hottest stars known, with a surface temperature of 200,000 degrees C.
NGC 2467 is an open star cluster embedded in a different kind of nebula, where a star is not dying, but many stars are being born. It is vast concentration of gas and dust that is coalescing into new stars, 13,000 light years away. It is often referred to as the Skull And Crossbones Nebula, with a magnitude of 7.1.
|Winter: Orion Canis Major Canis Minor Monoceros Lepus Eridanus Taurus Auriga Camelopardalis Lynx Gemini Cancer|
|Spring: Hydra Sextans Crater Corvus Leo Leo Minor Ursa Major Ursa Minor Canes Venatici Coma Berenices Virgo Bootes|
|Summer: Draco Corona Borealis Hercules Ophiuchus Serpens Libra Scorpius Sagittarius Scutum Aquila Sagitta Vulpecula Lyra Cygnus|
|Autumn: Andromeda Perseus Pegasus Cassiopeia Cepheus Cetus Lacerta Delphinus Equuleus Capricornus Aquarius Pisces Aries Triangulum|
|Southern Skies: Centaurus Crux Lupus Corona Australis Piscis Australis Sculptor Tucana Fornax Dorado Columba Puppis Carina Vela|