26-04-2008 Naming the stars (Article 134)

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Simon Kenny
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26-04-2008 Naming the stars (Article 134)

Post by Simon Kenny » Fri Jan 02, 2009 4:20 pm

Naming the stars (Article 134)

How did the stars get their names? In ancient times those observing the night sky named them for something that had significance in their daily lives or their beliefs. Today, stars are given various different names and designations. Many of the proper names of stars that we continue to use today are of Arabic origin. Beautiful names such as Aldebaran (the follower), Betelgeuse from original Arabic yad al-jauza (hand of al-jauza), while others are Greek, such as Sirius (scorching). Of course other cultures also had their star names, with such wonderful examples like the Polynesian Ke Ali’i-o-kona-I-ka-iewa (Chief of the Southern Heavens) for the star we know as Canopus.

In more modern times, stars were labelled with Greek letters, like Alpha, maps using the lower case Greek letters (as seen in mathematical equations). This system was introduced in 1603 by Bayer and has been universally adopted since then. Those stars not assigned a Greek letter are instead known by a number and the genitive form of the constellation within which they reside, as seen from Earth. Examples are 10 Ursa Majoris. These are called Flamsteed numbers, after the first English astronomer royal, John Flamsteed, who compiled the list in the late 17th century.

Many stars vary in brightness, and are thus called variable stars, and subject of a future article. These are given a different designation to identify them in variable star catalogues, are assigned capital Roman letters, beginning with the letter R, and again the genitive of their constellation. Examples are R Andromedae. The brighter variable stars that already have Bayer letters, such as Chi Cygni, also retain this designation. Other stars are named after astronomers who either catalogued them for class attributes or discovered unusual properties of the star. Examples are Wolf 359 (made somewhat ‘famous’ as the location of a major battle in a Star Trek TNG episode), and Andrew’s star, named after an astronomer at Armagh Observatory.

The majority of stars not visible to the unaided eye have somewhat unromantic numerical designations, based upon the catalogue in which they reside, such as The Hubble Guide Star catalogue used by software programmers to point the telescope. Indeed many stellar catalogues now exist, and thus a single star may have many names associated with it, so that all in all, stellar nomenclature can be highly confusing.

While this may seem unwieldy and somewhat daunting, astronomers are not the only people to bring such complexity to their passion. In botanical circles for example, plants can have a number of names as well. Take the flower Picxis echioides, also known by the names Bristly Oxtongue, or Composiate or Asteraceae, or to those less informed, a dandelion, (though in fact it is only related to the dandelion family).

Fortunately for those starting out in astronomy, the system of proper names, Bayer letters and Flamsteed numbers remain the most commonly used for stars visible to the unaided eye.

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