Pyxis

Hydra IAU

Constellation Pyxis

Sidney Hall - Urania's Mirror - Noctua, Corvus, Crater, Sextans Uraniæ, Hydra, Felis, Lupus, Centaurus, Antlia Pneumatica, Argo Navis, and Pyxis Nautica

Tpyx hst big

NGC 2818 by the Hubble Space Telescope

Pyxis is a small and faint constellation in the southern sky. Its name is Latin for a mariner's compass, which distinguishes it from Circinus, which represents a draftsman's compasses. Pyxis was introduced in the 18th century by the French astronomer Nicolas Louis de Lacaille, who originally named it Pyxis Nautica. It is located between the constellations of Hydra, the sea serpent, and Puppis, the stern of the ship, which were part of the larger constellation of the ship Argo Navis before it was divided into several smaller constellations. Despite its small size and faint stars, Pyxis has several interesting features for amateur astronomers, including a number of galaxies and star clusters.

History and Mythology

Unlike many of the constellations, which date back to antiquity and have rich mythologies associated with them, Pyxis does not have any myths directly associated with it. It was introduced by Lacaille during his expedition to the Cape of Good Hope, where he cataloged the stars of the southern hemisphere. Lacaille named many constellations with names that reflected the scientific instruments of the Enlightenment era, and Pyxis represents the navigational compass used by sailors.

Characteristics

Pyxis is a small constellation bordered by Hydra, Antlia, Puppis, and Vela. It is best visible in the southern hemisphere during the late summer months. The constellation's brightest star is Alpha Pyxidis, a magnitude 3.68 star, which is relatively faint compared to stars in more prominent constellations.

Notable Features

Among the notable features in Pyxis are several deep-sky objects that are of interest to astronomers. These include:

- NGC 2613: A spiral galaxy situated about 60 million light-years away. It is seen edge-on from Earth, presenting a slender profile against the backdrop of stars. - NGC 2818: A planetary nebula that is also part of an open star cluster. This rare combination makes NGC 2818 particularly interesting for study. - T Pyxidis: A recurrent nova system in Pyxis. It has had several outbursts recorded, making it a subject of interest for understanding the dynamics of nova systems.

Observation

Pyxis is best observed from the southern hemisphere during the months of February, March, and April. While it does not contain any stars brighter than magnitude 3, its position in the sky away from the Milky Way's bright band means that its fainter objects can be observed with less interference from galactic light.

In Culture

Due to its relatively recent introduction and lack of mythological significance, Pyxis does not have a prominent place in cultural references compared to older and more mythologically rich constellations.

See Also

• Nicolas Louis de Lacaille
• Argo Navis
• Constellation