- WASHINGTON (www.nando.net) - The Hubble Space Telescope has captured a turning
point in the death of a Sun-like star: the instant when the hydrogen and
helium at the star's core are flung into interstellar space to create more
heavenly bodies.
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- "This is probably very much like
what will happen to the Sun," astronomer William Latter said Thursday
as the new Hubble images were released by the Space Telescope Science Institute.
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- However, our Sun is much younger than
the star snapped in the new pictures, and will not approach this phase
for about 4.5 billion years, Latter said in a telephone interview from
the California Institute of Technology.
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- This brief period in the stellar death
process actually lasts about 1,000 Earth years, a mere blink in cosmological
time.
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- When a star starts to die, Latter said,
the nuclear fuel at its heart runs out and a very dense, cool shell of
hydrogen molecules is deposited around the star. This molecular shell cannot
be seen, but Hubble's infrared camera snapped its image.
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- The dying star in question, known as
NGC7027 and located 3,000 light-years from the Sun in the direction of
the constellation Cygnus the Swan, is seen in the new pictures as a glowing
white ball surround by red wisps of the dissipating molecular shell.
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- The molecular shell is atomized and the
resulting atoms are flung into space as the most primitive building blocks
for other stars, planets and any life that may form on them, Latter said.
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- "What's new about these images is
we're able to see a very thin transition between the ionized region and
the formerly invisible atmosphere on the star," he said.
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- Also on Thursday, the telescope institute
released images of two other dying stars that look like butterflies emerging
from their cocoons.
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- These two -- known as the Cotton Candy
nebula and the Silkworm nebula -- show the moribund stars blowing off shells
of gas that surrounded them after their nuclear cores were exhausted.
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- The gaseous shells give the stars their
butterfly-wing shape, astronomers said in a statement.
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