Pyxis

Pyxis is located close to the stars that formed the old constellation Argo Navis, the ship of Jason and the Argonauts.

[3] In ancient Chinese astronomy, Alpha, Beta, and Gamma Pyxidis formed part of Tianmiao, a celestial temple honouring the ancestors of the emperor, along with stars from neighbouring Antlia.

[7] The Ancient Greeks identified the four main stars of Pyxis as the mast of the mythological Jason's ship, Argo Navis.

[8] German astronomer Johann Bode defined the constellation Lochium Funis, the Log and Line—a nautical device once used for measuring speed and distance travelled at sea—around Pyxis in his 1801 star atlas, but the depiction did not survive.

[9] In 1844 John Herschel attempted to resurrect the classical configuration of Argo Navis by renaming it Malus the Mast, a suggestion followed by Francis Baily, but Benjamin Gould restored Lacaille's nomenclature.

[7] For instance, Alpha Pyxidis is referenced as α Mali in an old catalog of the United States Naval Observatory (star 3766, page 97).

[12] A small constellation, it is bordered by Hydra to the north, Puppis to the west, Vela to the south, and Antlia to the east.

[13] The official constellation boundaries, as set by Belgian astronomer Eugène Delporte in 1930, are defined by a polygon of eight sides (illustrated in infobox).

[14] Lacaille gave Bayer designations to ten stars now named Alpha to Lambda Pyxidis, skipping the Greek letters iota and kappa.

[17] The second brightest star at magnitude 3.97 is Beta Pyxidis, a yellow bright giant or supergiant of spectral type G7Ib-II that is around 435 times as luminous as the Sun,[20] lying 420 ± 10 light-years distant away from Earth.

[18] It is an orange giant of spectral type K3III that has cooled and swollen to 3.7 times the diameter of the Sun after exhausting its core hydrogen.

[22] Kappa Pyxidis was catalogued but not given a Bayer designation by Lacaille, but Gould felt the star was bright enough to warrant a letter.

[24] Theta Pyxidis is a red giant of spectral type M1III and semi-regular variable with two measured periods of 13 and 98.3 days, and an average magnitude of 4.71,[25] and is 500 ± 30 light-years distant from Earth.

[18] The system emits X-rays, and analysing the emission curve over time led researchers to conclude that there was a loop of material arcing between the two stars.

[38] VY Pyxidis is a BL Herculis variable (type II Cepheid), ranging between apparent magnitudes 7.13 and 7.40 over a period of 1.24 days.

[45] A red dwarf of spectral type M2.5V that has around 42% the Sun's mass, Gliese 317 is orbited by two gas giant planets.

[46] Pyxis lies in the plane of the Milky Way, although part of the eastern edge is dark, with material obscuring our galaxy arm there.

The surface temperature of one component has been estimated at as high as 85,000 K.[49] NGC 2627 is an open cluster of magnitude 8.4 that is visible in binoculars.

[50] Located in the galactic halo, it was noted to lie on the same plane as the Large Magellanic Cloud and the possibility has been raised that it might be an escaped object from that galaxy.

Pyxis is positioned just south of the star Alphard in the constellation Hydra midway between Virgo and Cancer . Although it is completely visible from latitudes south of 53 degrees north , its best evening-sky visibility is during February and March in the southern hemisphere.
The constellation of Pyxis, the compass, as it can be seen by the naked eye
A 19th century coloured engraving of a group of constellations in the Southern Celestial Hemisphere in this plate from Urania's Mirror (1824).
Pyxis can be seen overlying the mast of Argo Navis
An image of a central white object surrounded by white and pale blue markers signifying material in a shell-like pattern around it
Hubble Space Telescope picture of T Pyxidis , showing ejected material from past eruptions
A coloured oval cloud of material against a dark background
The planetary nebula NGC 2818, imaged by the Hubble telescope