Bar At Milky Way's Heart Revealed

[zavvy]

<b>Bar At Milky Way's Heart Revealed</b><br /><br />LINK<br /><br />The Milky Way is not a perfect spiral galaxy but instead sports a long bar through its centre, according to new infrared observations from NASA's Spitzer Space Telescope.<br /><br />Galaxies come in a wide variety of shapes usually thought to be produced by gravitational interactions with nearby objects. Some spiral galaxies look like pinwheels, with their arms curving out from a central bulge, while others have a straight bar at their centres. <br /><br />Radio telescopes detected gas that hinted at a bar at the heart of the Milky Way in the late 1980s. A decade later, observations with the near infrared survey 2MASS bolstered the case for a bar, but dust in the centre of the galaxy obscured the observations.<br /><br />Now, astronomers have used Spitzer to peer through that dust at slightly longer wavelengths, observing 30 million stars in the galactic plane in the region around the centre of the galaxy. <br /><br />They found that the central bar was much longer than previous observations had suggested - reaching about half the distance between the galaxy's centre and our Sun. The bar is estimated to stretch a total of about 27,000 light years from end to end. <br /><br />"It is a major component of our galaxy and has basically remained hidden until now," says team member Ed Churchwell, an astronomer at the University of Wisconsin in Madison, US. "The fact that it's large means it's going to have a major effect on the dynamics of the inner part of our galaxy."<br /><br />Bar food<br />Stars in the spiral arms circle the galaxy in roughly circular orbits. But the old, red stars in the bar appear to be on more elliptical paths that take them more directly towards and away from the galaxy's core, where a colossal black hole is thought to lurk. <br /><br />"This bar probably does carry matter into the centre of the galaxy and feeds the bl

 

[lunatio_gordin]

Definitely interesting. Means we aren't just like Andromeda or M51.

 

[CalliArcale]

Nope. It means we're a barred spiral, possibly like this one: APOD for Jan 12 2005: Barred Spiral Galaxy NGC 1300.<br /><br />Alternately, we might look more like this one: APOD for May 25, 1998: M83: A Barred Spiral Galaxy <br /><br />Here's a really classic-shape barred spiral:<br />APOD for April 13, 2003: NGC 1365: A Nearby Barred Spiral Galaxy <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>

 

[lunatio_gordin]

I thought there was, like... 8 arms in the milky way? we're in the Orion arm, right? does this change that? i'm trying to imagine a Barred Spiral with 8 arms...

 

[formulaterp]

Look at the first link CalliArcale provided. You can make out 3 or 4 arms in the "top half" of the galaxy. Our Orion arm may look similar.

 

[lunatio_gordin]

I guess you mean the second one?<br />At any rate, it's defintely not like what they told us in school <img src="/images/icons/tongue.gif" />

 

[Grok]

Dang, and here I was thinking ...let's go have a drink <img src="/images/icons/wink.gif" />

 

[Grok]

At least we aren't a backwater planet on an insignificant arm of a spiral galaxy anymore.

 

[lunatio_gordin]

Make that Backwater planet on the insignificant arm of a Barred Spiral, then <img src="/images/icons/tongue.gif" />

 

[formulaterp]

I can't seem to get the newscientist article to load, but here's a link from UofWisc with an artist's impression of what the Milky Way might look like:<br /><br />http://www.news.wisc.edu/newsphotos/milkyway.html

 

[lunatio_gordin]

wow. Actually, that's way cooler looking.

 

[zavvy]

<font color="yellow">...let's go have a drink...</font><br /><br />Ok, make mine a large Pan-Galactic Gargle Blaster... <img src="/images/icons/wink.gif" />

 

[Grok]

I was thinking that "Bar at Milky Way's Heart" sounds like a title to the Hitchhiker series.

 

[llivinglarge]

Homer Simpson: Mmmm... Milky Way Bar...