Galactic Centre Starscape
Thirty thousand light-years distant,
beyond the
majestic dust clouds of the constellation
Sagittarius, lies the centre of our Milky Way Galaxy.
Hidden from optical view by the dust, the
Galactic Centre region is
a relatively unexplored starscape.
But
infrared light can more easily
penetrate the dust and
this recently released
Infrared Space Observatory
(ISO)
mosaic, together with other similar images, shows about 100,000 previously
unseen stars of the Milky Way's central regions.
Huge obscuring dust clouds still seem to crowd the area
especially in the left part of the infrared picture.
Marked by the white circle, the centre itself is missing from the mosaic
because it is so bright that it would saturate ISO's sensitive camera.
The stars
are mostly evolved
red giants, intrinsically cool,
large, bright stars that have swollen after exhausting their central supply
of hydrogen fuel.
The detailed properties of the
red
giant stars can be
very revealing
as these stars contribute to the interstellar
gas and dust clouds, enriching their galactic environment with
carbon and
other elements.
Their motions also trace the mass distribution in the Galactic Centre and
may support the idea that our Galaxy grew by
swallowing smaller, nearby galaxies.