Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.sai.msu.su/groups/cluster/efremov/figures/ori.txt Дата изменения: Thu Nov 6 17:58:02 1997 Дата индексирования: Sat Dec 22 07:19:43 2007 Кодировка: Поисковые слова: rigel

Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our
fascinating universe is featured, along with a brief explanation
written by a professional astronomer.

December 2, 1996
[LINK]

Orion's Star Colors
Credit and Copyright: David Malin

Explanation: What determines a star's color? Its temperature. Red
stars are cool, with temperatures of around 3,000 degrees Kelvin (K),
while blue stars are hotter and can have temperatures over 30,000
degrees K. Our own lovely yellow Sun's temperature is a comforting
6,000 degrees K. Differences in star colors are dramatically
illustrated in the above photo of the constellation Orion, made using
a "star trail step-focus" technique. In this technique, a time
exposure is used to create star trails, but during the exposure, the
focus is changed in steps. For the brighter stars, the blurred image
produces more saturated colors in photographs. At the upper left, the
cool red supergiant Betelgeuse stands out from the other, hotter,
bluish stars composing the body of the constellation. Bright Rigel, a
blue supergiant, is at the lower right.

Tomorrow's picture: Cocoon of a New White Dwarf

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