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BLACK
HOLES CONFIRMED
The
question of what lies in the center of our Milky Way Galaxy has been one
of science's major unanswered questions.
NSF-funded researcher Andrea Ghez has confirmed the presence of an enormous
black hole at the center of our galaxy, providing new understanding of
how galaxies evolve.
Black holes are normally formed from the remnants of collapsed stars.
However, near the centers of galaxies it is believed that enough matter
can collect from stellar collisions and the accumulation of interstellar
gas to form a black hole.
A black hole consists of a large mass compacted so densely that not even
light can escape its force of gravity. In 1995, Ghez began tracking the
movement of 200 stars near the center of our galaxy, finding at
least 20 stars moving as if they were in orbit around an invisible object
about one million times the sun's mass.
Using a technique in which computers analyze thousands of high-speed,
high-resolution snapshots to correct for the turbulence in the Earth's
atmosphere that ordinarily blurs images, Ghez
witnessed the disappearance of a star that was then the closest object
to the black hole.
Whether the star was sucked into the black hole or moved behind it may
never be known. A similar fate for Earth is not a concern, since the center
of the Milky Way Galaxy is approximately 24,000 light years away.
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