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Lectures on Stellar Statistics

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Published: 1921
Language: English
Wordcount: 18,362 / 71 pg
Flesch-Kincaid Reading Ease: 60.7
LoC Category: Q
Downloads: 659
Added to site: 2007.07.28
mnybks.net#: 17743
Origin: gutenberg.org
Genres: Science,
Excerpt

50[3]), but considering that the Pole-star ([alpha] Ursæ Minoris) is used at Harvard as a fundamental star of comparison for the brighter stars, and that, according to the observations at Harvard and those of HERTZSPRUNG (A. N. 4518 [1911]), the light of the Pole-star is very nearly invariable, we may say that the zero-point of the photometric scale is chosen in such a manner that for the Pole-star m = 2.12. If the magnitudes are given in another scale than the Harvard-scale (H. S.), it is necessary to apply the zero-point correction. This amounts, for the Potsdam catalogue, to -0m.16.

It is further necessary to determine the scale-ratio. Our magnitudes for the stars emanate from PTOLEMY. It was found that the scale-ratio--giving the ratio of the light-intensities of two consecutive classes of magnitudes--according to the older values of the magnitudes, was approximately equal to 2½. When exact photometry began (with instruments for measuring the magnitudes) in t

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William A. Liggett
Some of Bill Liggett's earliest memories are of climbing over the rocks near their family cabin in the mountains. He has always had a love for nature and a keen interest in science, which inspired him to start writing books in the "cli-fi" genre, where behavioral and earth sciences are blended to create riveting fiction. As our Author of the Day, Liggett talks about his book, Watermelon Snow, his research and reveals why he put a positive spin on a book about global warming.
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