January 6, 2009—The first infrared panorama of the Milky Way's center (detail of the full panorama above) has revealed a previously unknown population of massive stars scattered across the turbulent zone around our galaxy's core.
A composite of Hubble and Spitzer space-telescope observations, the panorama covers a 300-by-115-light-year area with a high enough resolution that—even at a distance of 26,000 light-years from Earth—objects as small as 20 times the size of our solar system are brought to light.
Among these object are about 26 million stars, 300 of which can be identified as massive stars that are relatively young—a few million years old or less. About two-thirds of those 300 are single stars that are unexpectedly lying outside the three known clusters of star formation.
"Because these stars are in isolation, they either formed this way or they spun out recently from very massive star clusters," said study leader Q. Daniel Wang, of the University of Massachusetts.
The new view also gives scientists the sharpest look yet at odd structures within the galactic core, including fluffy fingers of gas sculpted by winds streaming from a large star cluster (lower left) and the pinwheel of material spiraling into the supermassive black hole at our galaxy's heart (lower right).
"This is an important step in establishing the center of our galaxy as a laboratory to study the complex interactions between massive stars and the harsh environments of the nuclear regions of galaxies in general," Wang said.
He and colleagues unveiled the new image Monday at an American Astronomical Society meeting in Long Beach, California.