As Argo Navis was roughly 28% larger than the next largest constellation,Hydra,[2] it was sub-divided into three sections in 1752 by the French astronomerNicolas Louis de Lacaille, including Puppis, which he referred to as "Argûs in puppi". Despite the division, Lacaille kept a single set ofBayer designations for the whole constellation, Argo. Therefore, Carina has the α, β, and ε, Vela has γ and δ, Puppis has ζ, and so on.[3] In 1844,John Herschel proposed complete dividing Argo Navis in accordance with Lacaille's divisions.[4] However, the constellation continued to be used into the 20th century, and officially received a three-letter designation alongside its divisions in 1922.[5] Puppis, along with Carina and Vela, was included in the list of modern IAU constellations in 1930.[6]
Severalextrasolar planet systems have been found aroundstars in the constellation Puppis, including:
On July 1, 2003, aplanet was found orbiting the starHD 70642. Thisplanetary system is much likeJupiter with a wide, circular orbit and a long-period.
On May 17, 2006,HD 69830 was discovered to have three Neptune-mass planets, the first multi-planetary system without any Jupiter-like orSaturn-like planets. The star also hosts anasteroid belt at the region between middle planet to outer planet.
On June 21, 2007, the first extrasolar planet found in theopen clusterNGC 2423, was discovered around thered giant starNGC 2423-3. The planet is at least 10.6 times the mass of Jupiter and orbits at 2.1AU distance.
On September 22, 2008, two Jupiter-like planets were discovered aroundHD 60532.HD 60532 b has aminimum mass of1.03MJ and orbits at 0.759 AU and takes 201.3 days to complete the orbit.HD 60532 c has a minimum mass of2.46MJ and orbits at 1.58 AU and takes 604 days to complete the orbit.
As theMilky Way runs through Puppis, there are manyopen clusters in the constellation.M46 andM47 are two open clusters in the same binocular field. M47 can be seen with the naked eye under dark skies, and its brightest stars are 6th magnitude.Messier 93 (M93) is another open cluster somewhat to the south.NGC 2451 is a very bright open cluster containing the starc Puppis, and the nearNGC 2477 is a good target for small telescopes. The starPi Puppis is the main component of a bright group of stars known asCollinder 135.
M46 is a circular open cluster with an overall magnitude of 6.1 at a distance of approximately 5400 light-years fromEarth. Theplanetary nebulaNGC 2438 is superimposed; it is approximately 2900 light-years from Earth. M46 is classified as a Shapley class f and a Trumpler class III 2 m cluster. This means that it is a rich cluster that appears distinct from the star field, despite not being at its center. The cluster's stars, numbering between 50 and 100, have a moderate range in brightness.[7]
