Bar of stars slices through Milky Way

Discoveries

August 19, 2005

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 of 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, to appear in a future edition of Astrophysical Journal Letters, a leading astronomy journal, 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.

--- Associated Press

Quick Takes

Pill for hangovers

A new little purple pill promises to take the edge off foggy hangovers and attack the toxic properties of alcohol.

Cheerz Hangover Pills, available on the Internet, are the latest dietary supplements that promise to let you drink cocktails at night without a headache in the morning. They sell for $47.88 for a dozen, eight-pill packages, plus shipping.

Most hangover pills, such as leading-seller Chaser, use activated carbon and calcium carbonate to filter additives to liquor called congeners that are linked to hangovers.

Cheerz uses natural succinic acid to help the body slow and reduce the conversion of alcohol to a harmful chemical called acetaldehyde, say company officials.

National Institutes of Health scientists this month released studies that begin to explain how acetaldehyde plays a role in linking alcohol to higher cancer rates. Scientists remain skeptical, though, about whether a pill can negate these negative aspects of drinking.

Bottom Line: This pill may hold promise for more than simply getting rid of a hangover. But the wisest course of action is to avoid overindulging.

-- Mary Beth Regan

Did you know...

The mosquito-borne West Nile virus is relatively new to the United States, having made its first known appearance in 1999 during an outbreak in New York City. In 2004, there were more than 2,500 U.S. cases and 98 deaths. You can reduce your risk of contracting West Nile by avoiding exposure to mosquitoes.

-- Mayo Foundation for Medical Education and Research

In Brief

Furry mice and tumor therapy

By making mice grow furrier coats, researchers have discovered that an enzyme known to serve as a last-ditch defense against cancer also activates adult stem cells, which the body uses to repair its tissues.

The insight could lead to new treatments for certain diseases, possibly even promoting hair growth in animals other than mice.

The research, reported Wednesday by Steven E. Artandi and colleagues at Stanford University in Nature, shows that adult stem cells can be activated by an enzyme called telomerase.

The finding is surprising because telomerase is well-known in a quite different context, protecting against tumors by limiting the number of times a cell can divide. The new findings put the enzyme astride two major biological pathways, one that promotes the growth of new cells for maintaining tissues and the other that prevents the excessive growth that leads to tumors.

The finding is "very interesting and very tantalizing," said Carol Greider, a telomerase expert at the Johns Hopkins University, who was not involved in the research

Artandi chose to study the effects of telomerase on mouse fur not to develop a hair-replacement therapy for rodents, but because mice have an easily accessible stem cell system built into their skin.

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