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Астронет: Астрономическая картинка дня IC 2118: туманность Голова Ведьмы http://variable-stars.ru/db/msg/1909562/eng |
Credit & Copyright: Abdullah Alharbi
Explanation:
Does this nebula look like the head of a witch?
The nebula is
known popularly as the Witch Head Nebula because, it is said,
the nebula's shape resembles a
Halloween-style caricature of a witch's head.
Exactly how, though, can be a topic of imaginative speculation.
What is clear is that
IC 2118 is about 50
light-years
across and made of gas and dust that points to --
because it has been partly eroded by -- the nearby star
Rigel.
One of the brighter stars in the constellation Orion,
Rigel lies below the bottom of the
featured image.
The blue color of the Witch Head Nebula and is caused not only by
Rigel's intense blue starlight
but because the
dust grains
scatter blue light more efficiently than red.
The same physical process causes Earth's daytime
sky to appear blue,
although the scatterers in planet
Earth's atmosphere are molecules of
nitrogen
and
oxygen.
Authors & editors:
Robert Nemiroff
(MTU) &
Jerry Bonnell
(USRA)
NASA Web Site Statements, Warnings,
and Disclaimers
NASA Official: Jay Norris.
Specific
rights apply.
A service of:
LHEA at
NASA /
GSFC
& Michigan Tech. U.