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Астронет: Астрономическая картинка дня IC 4603: отражательная туманность в Змееносце http://www.variable-stars.ru/db/msg/1317874/eng |
Credit & Copyright: Rolf Olsen
Explanation:
Why does this starfield photograph resemble an
impressionistic painting?
The effect is created not by
digital trickery but by large amounts of
interstellar dust.
Dust, minute globs rich in
carbon and similar in size to
cigarette smoke, frequently starts in the
outer atmospheres of large, cool, young stars.
The dust is dispersed as the star dies and grows as things stick to it in the
interstellar medium.
Dense dust clouds are
opaque to
visible light and can completely hide background stars.
For less dense clouds, the capacity of dust to
preferentially reflect blue starlight becomes important,
effectively blooming the stars blue light out and marking the surrounding dust.
Nebular gas emissions, typically brightest in
red light,
can combine to form areas seemingly created on an artist's canvas.
Photographed above is the central part of the nebula
IC 4603 surrounding the bright star
SAO 184376 (actually
8th
magnitude)
which mostly illuminates the
blue reflection nebula.
IC 4603 can be seen near the very bright star
Antares (1st magnitude) toward
the
constellation of
Ophiuchus.
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