THE CONSTELLATIONS

From Jim Kaler's STARS.

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The Constellations thanks more than two million visitors.

A Brief Introduction

Constellations are named patterns of stars. All societies created them. The classical -- "ancient" -- constellations that populate our sky began in the lands of the middle east thousands of years ago, their origins largely lost to time. They passed through the hands of the ancient Greeks, who overlaid them with their legends and codified them in story and verse. During Roman times they were assigned Latin names.

The 48 ancient constellations single out only the bright patterns. From around 1600 to 1800, post-Copernican astronomers invented hosts of "modern" constellations from the faint stars that lie between the classical figures, from pieces of ancient constellations, and from the stars that occupy the part of the southern sky that could not be seen from classical lands. They also separated the ship Argo into three parts, yielding 50 ancient constellations.

In the early twentieth century, the International Astronomical Union (IAU) adopted 38 of the modern constellations and drew rectangular borders around all 88. Many of these contain informal constellations, or "asterisms," that are often the first to be learned, Ursa Major holding the "Big Dipper" and so on. Other asterisms, like the Winter Triangle, cut across constellation boundaries. Some constellations look like what they are supposed to represent, but most do not. Constellations, both ancient and modern, are generally meant to honor and represent, not to portray.

The constellations play an important role in modern astronomy. They bring order to the sky by dividing it into smaller segments, providing a base for naming celestial objects. Though the brighter stars commonly carry "proper names" that come mostly from Arabic, they are also assigned Greek letters and Arabic numbers to which are affixed the Latin possessive forms of the constellation names, Vega, for example, also known as "Alpha of Lyra," or "Alpha Lyrae." The IAU also adopted three-letter abbreviations for all the constellations and their possessives, Vega thus becoming Alpha Lyr. The accepted constellations are listed alphabetically in the table below. The columns give, in order:

• The constellation name.
• The constellation's meaning (if appropriate, linked to a tale in Stellar Stories).
• The Latin possessive form.
• The three-letter abbreviation.
• The location (linked to its Constellation Map), as follows:
  • E: Equatorial; lying on the celestial equator
  • EN: Equatorial north; lying between the celestial equator and 45 degrees north of the equator.
  • NP: North polar; north of 45 degrees north of the celestial equator; circumpolar for northern latitudes, not rising for far southern latitudes.
  • ES: Equatorial south; lying between the celestial equator and 45 degrees south of the equator.
  • SP: South polar; south of 45 degrees south of the celestial equator; circumpolar for southern latitudes, not rising for far northern latitudes.
  • Intermediate positions are indicated by combining location codes, a constellation lying across the circle 45 degrees north of the celestial equator called EN-NP and so on.
  • Constellations not on the Constellation Maps are indicated by an asterisk (*); their positions are described in the text of the appropriate map.
• The Luminary, or brightest star by both proper and Greek- letter name (or number). Many luminaries, especially those of southern constellations, have no proper name.
• Remarks. These include whether the constellation is modern, references to mythology, some asterisms, and what poles (equatorial, ecliptic, galactic) the constellation may contain.
• The constellations and their luminaries are linked to the main "Stars" page. Please enjoy them, both here and in the nighttime sky.