Our galaxy's sexier cousin
Posted: Tuesday, April 03, 2007 6:40 PM by Alan Boyle
NASA / ESA / STScI / AURA |
The galaxy NGC 1672 sparkles in a new image from the Hubble Space Telescope.
|
Using the Hubble Space Telescope, astronomers have produced a sparkling new picture of a spiral galaxy called NGC 1672 - a distant relative of our own Milky Way, only sexier.
When I say "distant," I'm talking in terms of literal distance: NGC 1672 is 60 million light-years away, in the southern constellation Dorado. And when it comes to the galaxy's relationship to our home galaxy, astronomers see some interesting similarities as well as differences.
Like the Milky Way, NGC 1672 has four major spiral arms that are linked to a straight "bar" of stars and dust. NGC 1672 is just a little smaller than the Milky Way, and both galaxies are apparently anchored at their cores by supermassive black holes. All this leads Joe Liske, a German astronomer at the European Southern Observatory, to call NGC 1672 a "sister galaxy" in a video podcast presented by the European Space Agency's Hubble Information Center.
But unlike the relatively mild-mannered Milky Way, NGC 1672's nucleus is thought to be ablaze with activity, although that blaze is muted by veils of dust.
Might our galaxy light up in the same way, or is it finished with its hot-blooded phase? That’s one of the big questions - and one of the reasons why astronomers are interested in active galaxies like NGC 1672 (which is technically classified as a Seyfert galaxy).
They're also curious about the distinction between barred and non-barred spiral galaxies. The central galactic bars may help channel gas from the outlying disk into the nucleus, sparking new waves of star formation - but what are the dynamics of that process? Scientists believe that the bars are relatively short-lived, recurring phenomena - but where do they fit in the cycle of galactic evolution? These are more questions waiting to be answered.
There's no question that NGC 1672 is a stunner: In Hubble's image, based on data collected by the Advanced Camera for Surveys in 2005, young hot stars show up as flashes of blue and violet sparkling around the edges of the spiral arms. Stars and galaxies far beyond NGC 1672 take on a reddened hue, due to the galaxy's intervening veils of dust. Foreground stars in the Milky Way pump up the bling as well.
The ESA's main Web site and its Hubble Information Center offer plenty of stills and videos focusing on NGC 1672, including the aforementioned "Hubblecast" video podcast. The Space Telescope Science Institute's Hubblesite provides yet another perspective on today's image release.
To keep up with the latest from Hubble, you can sign up for the institute's "Inbox Astronomy" e-mail bulletins - and to revel in the telescope's past glories, check out our Space Gallery for Hubble's greatest hits. Our latest "Month in Space" collection includes a galaxy portrait that's literally smashing.
