“This
is probably very much like what will happen to the Sun.”
—astronomer
William Latter
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A
false color image of the star NGC7027, located 3,000 light-years from Earth.
The three main colors in the image represent three different layers of
material ejected by the dying star. (NASA) |
By Deborah Zabarenko
March
19 — 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.
“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.
The institute released similar images of other dying stars last December.
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.
The Final
Millenium
The dying star that
astronomers have nicknamed ‘Cotton Candy.’ (NASA) |
This brief period in the stellar death process actually
lasts about 1,000 Earth years, a mere blink in cosmological time.
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.
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.
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.
New Details
NGC 3918 is another
dying star that has been observed by the Hubble Space Telescope. (NASA) |
“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.
Also on Thursday, the telescope
institute released images of two other dying stars that look like butterflies
emerging from their cocoons.
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.
The gaseous shells give the
stars their butterfly-wing shape, astronomers said in a statement.
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