It is available online to the public at and also can be purchased on CD-ROM.Hello! My name is Lathyrus, although some people may still remember me as BardlyMissed. The Guide Star Catalog is so large it is stored and read electronically. Once the telescope locks onto the guide stars, it remains pointed until the time exposure is complete,” Teske said. To point it accurately, the telescope’s controllers select a few of the 20 million guide stars and designate which of them must appear in which of the telescope’s sensors. “Hubble has very precise and sensitive light sensors for locating stars. It was compiled by the Space Telescope Science Institute for use with the Hubble Space Telescope. Consequently, astronomers sometimes speak of it as ‘HD 432.’ Because it is a prominent star in the sky, Caph has been enrolled into many star lists, so it sometimes goes under peculiar aliases like ‘+58,0003,’ ‘HR21’ or ‘SAO 21609.'”Īccording to Teske, the largest directory of celestial objects is the Space Telescope Guide Star Catalog, which contains 20 million entries giving exact sky positions for stars, galaxies and other features.

“Caph appears as the 432nd star on the roster. “This task took one person four years to complete,” Teske said. One of the best known lists was created at Harvard Observatory almost a century ago to classify 224,300 of the brighter stars according to a characteristic related to their temperatures. Each time a star is put on a listing, it gains a new name. Many other names have been given to stars by astronomers who inventory them for research purposes, according to Teske. The first Greek letter, alpha, is reserved for the brightest star and the third one, gamma, for the third brightest, and so on,” Teske added.Īlpha Cassiopeiae is located next to Caph, at the left bottom of the “W.” It is also called Schedar, Arabic for “breast.” Gamma, located at the middle of the “W,” has no Arabic name. “The Greek letter beta, second in the Greek alphabet, tells that Caph is the second brightest star in Cassiopeia. For example,Caph also is called Beta Cassiopeiae. “Despite this, its Arabic name was inserted into the Greek conception of Cassiopeia around 400 years ago.” Modern rules for naming stars add to the grief of ordinary observers. Observers who face north while looking up at Cassiopeia will see the star called “Caph,” meaning the palm of a hand, on the left end of Cassiopeia’s upside-down “W.” “The star’s name comes from a star picture envisioned by the Arabic peoples that is very different from the Greek conception of the constellation,” Teske explained.

“To add to the confusion, modern astronomers apply their own rules for naming stars, with the result that each of Cassiopeia’s stars has many aliases,” Teske said. This same mixture of Greek and Arabic names is common in many constellations, according to University of Michigan astronomer Richard Teske.

Yet some of its stars carry Arabian names given by Arabian peoples. One of the oldest of the star patterns we recognize, it was recognized by the ancient Greeks. ANN ARBOR-Hanging nearly overhead in November’s mid- evening sky is the W-shaped constellation we know as Cassiopeia, Queen of Ethiopia.

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