Theos-Talk Archives (February 1998 Message tt00088)

Different facts that we learn from astronomy can widen our mental
pictures of the world and help with our deeper philosophical
thinking. Here's a new item in the news ...

-- Eldon

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Dwarf galaxy swallowed by Milky Way is visible in Sagittarius

WASHINGTON, Feb 13 (AFP) - The Milky Way swallowed a much
smaller, dwarf galaxy billions of years ago that now can be seen
in the Sagittarius constellation, US and British astronomers said
in a study published

The Sagittarius galaxy, taking its name from the constellation,
is a tenth the size of the Milky Way but has only one-millionth
of its mass, said astrophysicist Rosemary Wise of Johns Hopkins
University, in Baltimore, Maryland.

Attracted by our galaxy's gravitational pull, Sagittarius circled
the Milky Way 10 times in as many billions of years before it was
sucked in to its present position, where it was detected in 1994
by the different motion of its stars.

"Sagittarius has come right in ... it's close enough that you
can study individual stars in it the same way that you study
stars in our galaxy," Wise on Thursday told the annual conference
of the American Association for the Advancement of Science in
Philadelphia, Pennsylvania.

The discovery could lend support to a widely held theory that
many large galaxies, such as the Milky Way, were formed by the
slow accumulation of smaller galaxies.

Wise and her four colleagues have calculated that 10 percent of
the Milky Way's halo, or outermost stars, originally came from
dwarf galaxies that fused with ours over the past eight billion
years.