Posted by Davin Flateau on 17 Aug 2005 at 10:02 am.
Filed under Astronomy.
The Milky Way Galaxy is home to our sun, and billions of our closest friends and neighbors.
So what does the Milky Way look like? You’d think it would be an easy question to answer about our own galaxy, but astronomers have an interesting problem in trying to this out from our vantage point inside our galaxy. It’s not like we can just send a camera way up above the galaxy and return a photo - the distances and time involved in travelling thousands of light years are monstrous.
Can you imagine sitting on a street corner and having to draw a map of the entire city? Scientists have to do a lot of hard work to reconstruct what the Milky Way looks like from our vantage here on the inside.
We’ve figured out that we’re a spiral galaxy, like many we see in the Universe, but exactly what type and configuration has been up to debate. And new tools certainly help. New images from the Spitzer Space Telescope, which looks at the Universe in infrared light that travels through obscuring dust, are giving us our best idea yet of what our galaxy looks like.
This artist’s picture now represents our best estimate at what our galaxy looks like:
The most pronounced feature in our galaxy is the central bar, putting us in the category of a “barred spiral” galaxy, and this new study makes the bar even more prominent.
The new study provides the best estimates for the size and orientation of the bar, which are far different from previous estimates. It shows a bar, consisting of relatively old and red stars, spanning the center of the galaxy roughly 27,000 light years in length — 7,000 light years longer than previously believed. It also shows that the bar is oriented at about a 45-degree angle relative to a line joining the sun and the center of the galaxy.
Previously, astronomers debated whether a presumed central feature of the galaxy would be a bar structure or a central ellipse — or both. The new research, the Wisconsin astronomers say, clearly shows a bar-like
structure.
Exploration Place Theater Director Martin Ratcliife asks: “Milky Way has a central Bar - but what drinks does it serve?”
Davin Flateau
