Credit: NASA & ESA
This new NASA/ESA Hubble Space Telescope image presents the Arches Cluster,
the densest known star cluster in the Milky Way. It is located about 25
000 light-years from Earth in the constellation of Sagittarius (The
Archer), close to the heart of our galaxy, the Milky Way. It is, like
its neighbour the Quintuplet Cluster, a fairly young astronomical object at between two and four million years old.
The
Arches cluster is so dense that in a region with a radius equal to the
distance between the Sun and its nearest star there would be over 100
000 stars!
At least 150 stars within the cluster are
among the brightest ever discovered in the the Milky Way. These stars
are so bright and massive, that they will burn their fuel within a short
time, on a cosmological scale, just a few million years, and die in
spectacular supernova
explosions. Due to the short lifetime of the stars in the cluster, the
gas between the stars contains an unusually high amount of heavier
elements, which were produced by earlier generations of stars.
Despite
its brightness the Arches Cluster cannot be seen with the naked eye.
The visible light from the cluster is completely obscured by gigantic
clouds of dust in this region. To make the cluster visible astronomers
have to use detectors which can collect light from the X-ray, infrared,
and radio bands, as these wavelengths can pass through the dust clouds.
This observation shows the Arches Cluster in the infrared and
demonstrates the leap in Hubble’s performance since its 1999 image of same object.
