Milky Way Bar

The next instellar probe needs a Milky Way Bar onboard! It could
eventually crash land on some alien planet and some alien McGyver could
use it to power a radio. Actually that sounds more like the professor
on Gilligan's Island.

Milky Way has bar at center, astronomers say
Ryan J. Foley, Associated Press
August 17, 2005 MILKY0818

MADISON, Wis. - After creating the most detailed analysis yet of what
the Milky Way looks like, astronomers say a long bar of stars cuts on
an angle through the center of the galaxy that includes the sun and
planet Earth.

Some scientists have suspected the presence of the stellar bar, but the
survey led by two Wisconsin astronomers shows the bar is far longer
than previously believed, and at a specific angle.

The skinny bar is made up of old and red stars and is about 27,000
light years in length, about 7,000 light years longer than previously
believed. The bar is at a 45 degree angle to the line between our Sun
and the center of the galaxy and may put the Milky Way in a small class
of galaxies with the unusual shape, researchers say.

"We're pretty certain the extent and orientation of this bar because we
got more data than anybody else that has ever brought to bear on the
problem by a long shot,'' said Ed Churchwell, a University of
Wisconsin-Madison professor of astronomy who collaborated on the
project.

The team of astronomers used NASA's Spitzer Space Telescope to survey
more than 30 million stars in the center of the Milky Way. The orbiting
infrared telescope allowed the astronomers to see bright stars through
clouds of interstellar dust to draw a vivid portrait of the center of
the galaxy.

The new portrait will help astronomers understand how our galaxy looks
from the outside and "how it forms together in the big picture,'' said
lead study author Robert Benjamin, a UW-Whitewater professor of
physics.

"The stronger the bar the more influence it has on everything going on
in the galaxy,'' said Benjamin.

The study will appear in an upcoming edition of Astrophysical Journal
Letters, a leading astronomy journal.

The study should put to rest the idea held by some astronomers that an
ellipse is at the center of the galaxy's swirling arms, Churchwell
said.

"We've largely been ignorant of this very major structure in our galaxy
for all these years,'' he said.

The hardest work in the study was not observing the stars: the NASA
orbiting telescope took about 400 hours of observations. Researchers
spent five years preparing for the observation and almost one year
making sense of all the data.

The telescope, launched two years ago, is the largest infrared
telescope ever launched into space and is trailing the earth in an
orbit around the sun. It uses infrared light to penetrate clouds of gas
and dust that block astronomers' views from Earth.

The Milky Way is a large, spiral galaxy that contains the sun, solar
system and billions of stars that make a luminous band as seen by the
naked eye. Its precise size, shape and mass are still unknown.

Billions of galaxies make up the universe and are mostly spiral or
elliptical in shape. Galaxies that have stellar bars cut through the
center is rare, but not unheard of, scientists say.