Tucana is a southern constellation located south of Grus and Phoenix. It is near the South Celestial Pole, so it is not visible from the Northern Hemisphere. Tucana's most notable feature is the Small Magellanic Cloud (SMC).
History and MythologyTucana was introduced by Johann Bayer is the 17th century. Bayer named this constellation to celebrate the discovery of the toucan in South America. The name Tucana refers to this large, noisy, tropical bird.
Notable Objects
Alpha Tucanae is an orange giant of magnitude 2.9, and is 200 light-years away.
Beta Tucanae is a multiple star with almost identical components of magnitude 4.5. Its two brightest stars are 27 arcseconds apart, and require a telescope to separate. The third component is 10 arc minutes from this pair, and can be seen separately by the naked eye. Nevertheless, they all share a common motion through space, and are almost certainly related to one another. All three components are hot blue-white main sequence stars, and have at least one companion, making Beta Tucanae a sextuple system!
The Small Magellanic Cloud (SMC) is in Tucana. It is visible with the naked eye and resembles a detached piece of the Milky Way. A small telescope readily shows the clusters and nebulae associated with the Small Magellanic Clouds. It is an irregular galaxy about 200,000 light-years from the Milky Way. The SMC, along with the Large Magellanic Cloud, are two of the closest galaxies to the Milky Way, but are no longer believed to be in orbit around our galaxy.
47 Tucanae, also known as NGC 104, is one of the finest globular clusters in the sky. To the naked eye, it can be seen as a large, fuzzy star of 4th magnitude. It is the second largest and brightest globular in the sky, after Omega Centauri. It is almost the size of the full moon, and is about 13,000 light-years away. NGC 362 is another impressive globular which appears nearby.