Press Release

Hubble Celebrates its 19th Anniversary with a Fountain of Youth

By SpaceRef Editor
April 21, 2009
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To commemorate the Hubble Space Telescope’s 19 years of historic,
trailblazing science, the orbiting telescope has photographed a
peculiar system of galaxies known as Arp 194. This interacting group
contains several galaxies, along with a “cosmic fountain” of stars,
gas, and dust that stretches over 100,000 light-years.

The northern (upper) component of Arp 194 appears as a haphazard
collection of dusty spiral arms, bright blue star-forming regions, and
at least two galaxy nuclei that appear to be connected and in the
early stages of merging. A third, relatively normal, spiral galaxy
appears off to the right. The southern (lower) component of the galaxy
group contains a single large spiral galaxy with its own blue
star-forming regions.

However, the most striking feature of this galaxy troupe is the
impressive blue stream of material extending from the northern
component. This “fountain” contains complexes of super star clusters,
each one of which may contain dozens of individual young star
clusters. The blue color is produced by the hot, massive stars which
dominate the light in each cluster. Overall, the “fountain” contains
many millions of stars.

These young star clusters probably formed as a result of the
interactions between the galaxies in the northern component of Arp
194. The compression of gas involved in galaxy interactions can
enhance the star-formation rate and give rise to brilliant bursts of
star formation in merging systems.

Hubble’s resolution shows clearly that the stream of material lies in
front of the southern component of Arp 194, as evidenced by the dust
that is silhouetted around the star-cluster complexes. It is therefore
not entirely clear whether the southern component actually interacts
with the northern pair.

The details of the interactions among the multiple galaxies that make
up Arp 194 are complex. The shapes of all the galaxies involved appear
to have been distorted, possibly by their gravitational interactions
with one another.

Arp 194, located in the constellation Cepheus, resides approximately
600 million light-years away from Earth. It contains some of the many
interacting and merging galaxies known in our relatively nearby
universe. These observations were taken in January of 2009 with the
Wide Field Planetary Camera 2. Images taken through blue, green, and
red filters were combined to form this picturesque image of galaxy
interaction.

SpaceRef staff editor.