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Астронет: Астрономическая картинка дня Удивительная спираль в LL Пегаса http://www.astronet.ru/db/msg/1789290/eng |
Credit & Copyright: Jonathan Lodge
Explanation:
What created the strange spiral structure on the upper left?
No one is sure, although it is likely related to a star in a
binary star system entering the
planetary nebula phase, when its outer atmosphere is ejected.
The huge spiral spans about a third of a
light year across and, winding four or five
complete turns, has a regularity that is without precedent.
Given the expansion rate of the
spiral gas,
a new layer must appear about every 800 years,
a close match to the time it takes for the two stars to orbit each other.
The star system that created it is most commonly known as
LL Pegasi,
but also AFGL 3068 and IRAS 23166+1655.
The featured image was taken in near-infrared light by the
Hubble Space Telescope.
Why the spiral glows is
itself a mystery, with a leading hypothesis being
illumination by light reflected from nearby stars.
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.