Credit & Copyright: R. Elson and R. Sword
(IoA Cambridge),
NASA
Explanation:
This is NGC 1818,
a youthful, glittering cluster
of 20,000 stars residing in the
Large
Magellanic Cloud, 180,000 light-years away.
Pick a star. Any star.
Astronomers
might pick the unassuming bluish-white one (circled) which
appears
to be a hot newly formed white dwarf star.
What makes it so interesting?
The standard astronomical wisdom
suggests that stars over 5 times as massive as the
sun rapidly exhaust
their nuclear fuel and end their lives in a spectacular
supernova explosion.
With less than this critical mass
they evolve into red giants, pass through a relatively
peaceful planetary nebula phase,
and calmly fade away as
white dwarf stars like this one.
Except that as a member of the NGC 1818 cluster,
this new white dwarf would have evolved from
a red
giant star over 7.6 times as massive as the
sun -- which should have exploded!
Its discovery
will likely force astronomers to revise the
limiting mass estimate for supernovae upward.
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Публикации с ключевыми словами:
white dwarf - star cluster - NGC 1818 - белый карлик - звездное скопление
Публикации со словами: white dwarf - star cluster - NGC 1818 - белый карлик - звездное скопление | |
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