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  • Print publication year: 2011
  • Online publication date: June 2011

1 - The emergence of variable star astronomy – a need for observations



We can not expect to accomplish such hopes in a moment, for we have just begun our investigation.

– Friedrich W. A. Argelander, 1844

With Tycho Brahe's discovery of a “new star” in 1572, a powerful realization occurred. No longer could one assume the unchanging character of the skies, the belief since the time of Aristotle and reinforced by Christian dogma. As historian Helen Lewis Thomas remarked, “for the first time it was realized that a continual watch must be kept on the heavens and that observation must be continuous and systematic.”

This idea is the essence of variable star astronomy; it is important not only to observe what is new or changing, but also to keep a careful record of those events. The early history of variable star astronomy is a story of catalogs and charts. The publication and availability of these tools brought attention to the phenomenon of stellar variability, or changes in brightness, and led to the discovery of many more variables.

The awareness of a star's variability came with the discovery of a previously uncharted third-magnitude star in the constellation Cetus on August 13, 1596, by David Fabricius (1564–1617), a Protestant minister in Osteel, Ostfriesland. It became fainter over time and then disappeared after October. Later, the star was named ο Ceti in 1603 by Johann Bayer as he prepared his celestial atlas Uranometria. The star had also been called Mira, a name later applied to the class of long-period variable stars called Miras.

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