NASA's Spitzer finds Milky Way's blooming countryside
Washington: Using NASA's Spitzer Space Telescope, astronomers have found blooming stars in our Milky Way galaxy's more barren territories, far from its crowded core.
The images are part of the Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (Glimpse 360) project, which is mapping the celestial topography of our galaxy.
The map and a full, 360-degree view of the Milky Way plane will be available later this year. Anyone with a computer may view the Glimpse images and help catalogue features.
We live in a spiral collection of stars that is mostly flat, like a vinyl record, but it has a slight warp. Our solar system is located about two-thirds of the way out from the Milky Way's centre, in the Orion Spur, an offshoot of the Perseus spiral arm. Spitzer's infrared observations are allowing researchers to map the shape of the galaxy and its warp with the most precision yet.
While Spitzer and other telescopes have created mosaics of the galaxy's plane looking in the direction of its centre before, the region behind us, with its sparse stars and dark skies, is less charted.
"We sometimes call this flyover country. We are finding all sorts of new star formation in the lesser-known areas at the outer edges of the galaxy," said Barbara Whitney, an astronomer from the University of Wisconsin at Madison, who uses Spitzer to study young stars.
Whitney and colleagues are using the data to find new sites of youthful stars. For example, they spotted an area near Canis Major with 30 or more young stars sprouting jets of material, an early phase in their lives. So far, the researchers have identified 163 regions containing these jets in the Glimpse 360 data, with some of the young stars highly clustered in packs and others standing alone.
Robert Benjamin is leading a University of Wisconsin team that uses Spitzer to more carefully pinpoint the distances to stars in the galaxy's hinterlands. The astronomers have noticed a distinct and rapid drop-off of red giants, a type of older star, at the edge of the galaxy. They are using this information to map the structure of the warp in the galaxy's disk.
"With Spitzer, we can see out to the edge of the galaxy better than before. We are hoping this will yield some new surprises," said Robert Benjamin of the University of Wisconsin.
Benjamin presented the results at the 222nd meeting of the American Astronomical Society in Indianapolis.