Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.astronet.ru/db/xware/msg/apod/2008-09-04
Дата изменения: Thu Sep 4 10:35:46 2008
Дата индексирования: Thu Sep 11 02:08:26 2008
Кодировка:
Spokes in the Helix Nebula
Astronomy Picture of the Day
    


Spokes in the Helix Nebula
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Spokes in the Helix Nebula
Credit: Don Goldman, Sierra Remote Observatories
Explanation: At first glance, the Helix Nebula (aka NGC 7293), looks simple and round. But this well-studied example of a planetary nebula, produced near the end of the life of a sun-like star, is now understood to have a surprisingly complex geometry. Its extended loops and comet-shaped features have been explored in Hubble Space Telescope images. Still, a 16-inch diameter telescope and camera with broad and narrow band filters was used to create this sharp view of the Helix. The color composite also reveals the nebula's intriguing details, including light-year long, bluegreen radial stripes or spokes that give it the appearance of a cosmic bicycle wheel. The spoke features seem to indicate that the Helix Nebula is itself an old and evolved planetary nebula. The Helix is a mere seven hundred light years from Earth, in the constellation Aquarius.


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Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)
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NASA Official: Jay Norris. Specific rights apply.
A service of: LHEA at NASA / GSFC
& Michigan Tech. U.

Based on Astronomy Picture Of the Day

Publications with keywords: planetary nebula - Helix Nebula - NGC 7293
Publications with words: planetary nebula - Helix Nebula - NGC 7293
See also:
All publications on this topic >>