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Pyxis

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Pyxis is a small and faint constellation located in the southern sky.

Its name is a shortening of the Latin term Pyxis Nautica, which means a mariner's compass. This constellation is one of the 88 modern constellations recognized by astronomers. It covers a total area of 220.8 square degrees. This represents about 0.535% of the entire sky. Because it is in the Southern Celestial Hemisphere, it is visible to anyone located south of 52°N latitude.

Pyxis IAU
Pyxis IAU

It is most easily observed in the evening sky during the months of February and March.

The stars within Pyxis show us many different ways that celestial bodies behave. The three brightest stars are Alpha, Beta, and Gamma Pyxidis, which form a rough line. Alpha Pyxidis is a blue-white giant star located about 880 light-years away. This star is approximately 22,000 times as luminous as our Sun.

Tpyx hst big
Tpyx hst big

Beta Pyxidis is a yellow bright giant located 420 light-years away. It is about 435 times as luminous as the Sun and has a companion star. Gamma Pyxidis is an orange giant that has swollen to 3.7 times the diameter of the Sun. These stars demonstrate the vast differences in temperature, size, and brightness found in our galaxy.

Some objects in Pyxis undergo dramatic changes over time. T Pyxidis is a recurrent nova, which is a type of star system that flares up periodically. This system is a binary star composed of a white dwarf and a red dwarf. The two stars orbit each other very quickly, every 1.8 hours. The white dwarf pulls material away from its companion star. This material builds up until it is ejected, causing the system to brighten to a magnitude of 7.

Tpyx hst big
Tpyx hst big

This process has been observed to happen every few decades, including in 1890, 1902, 1920, 1944, 1966, and 2011.

History shows how astronomers have tried to organize the stars in this region. In 1752, the French astronomer Nicolas-Louis de Lacaille first described the constellation. He called it la Boussole, which is French for the marine compass. He created this name after cataloging nearly 10,000 southern stars during a stay at the Cape of Good Hope.

In 1844, John Herschel suggested renaming the constellation Malus, meaning the mast. He wanted to link it to the ancient ship Argo Navis. However, his suggestion was not followed, and the name Pyxis was restored.

Pyxis also contains evidence of worlds beyond our own solar system. Astronomers have used Doppler spectroscopy to find three star systems with confirmed exoplanets. One system includes a hot Jupiter named HD 73256 b. This large planet orbits its yellow star every 2.55 days.

Jupiter and moon
Jupiter and moon

Another system, Gliese 317, contains two gas giant planets orbiting a red dwarf. This red dwarf is only about 42% as massive as the Sun. These discoveries help scientists understand how planets form and move around different types of stars.

Deep-space objects in this region provide clues about the history of the Milky Way. The Pyxis globular cluster is a massive group of stars located 130,000 light-years away.

NGC 2818 by the Hubble Space Telescope
NGC 2818 by the Hubble Space Telescope

This cluster is approximately 13.3 billion years old. It sits in the galactic halo, a region where globular clusters were not previously expected to be found. Some researchers believe this cluster may have escaped from the Large Magellanic Cloud. Additionally, the constellation contains the planetary nebula NGC 2818, which sits within a dim open cluster.

Finally, Pyxis is connected to the larger structure of the cosmos. The plane of the Milky Way passes directly through this constellation. This means we are looking through the disk of our own galaxy when we observe Pyxis. The constellation is also located near the remnants of the ancient constellation Argo Navis. That large constellation was broken into smaller parts like Carina, Puppis, and Vela. By studying Pyxis, astronomers can better understand the relationship between individual stars, planetary systems, and the massive structures of our galaxy.

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🖼️ Images & Media (10)
File:Pyxis IAU.svg
Pyxis IAU.svg
File:Hydra IAU.svg
Hydra IAU.svg
File:Crab Nebula.jpg
Crab Nebula.jpg
File:Sidney Hall - Urania's Mirror - Noctua, Corvus, Crater, Sextans Uraniæ, Hydra, Felis, Lupus, Centaurus, Antlia Pneumatica, Argo Navis, and Pyxis Nautica.jpg
Sidney Hall - Urania's Mirror - Noctua,...
File:Earth-moon.jpg
Earth-moon.jpg
File:NGC 2818 by the Hubble Space Telescope.jpg
NGC 2818 by the Hubble Space Telescope.jpg
File:Constellation Pyxis.jpg
Constellation Pyxis.jpg
File:Tpyx hst big.jpg
Tpyx hst big.jpg
File:He1523a.jpg
He1523a.jpg
File:Jupiter and moon.png
Jupiter and moon.png
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