Galaxy Group Hickson 90
Explanation:
Scanning the skies for galaxies, Canadian astronomer
Paul Hickson and colleagues identified some 100 compact
groups
of galaxies, now appropriately called
Hickson Compact Groups (HCGs).
This sharp Hubble image
shows one such
galaxy group, HCG 90, in
startling detail.
Three galaxies -- two visible here -- are revealed to be strongly interacting:
a dusty
spiral galaxy
stretched and distorted in the image center, and two large
elliptical galaxies.
The close encounter will trigger
furious star formation.
On a cosmic timescale, the gravitational tug of war will eventually
result
in the merger of the trio into a large single galaxy.
The merger process is now understood to be a normal part of the evolution of
galaxies, including
our own Milky Way.
HCG 90 lies about 100 million light-years away toward
the constellation of the Southern Fish
(
Piscis Austrinus).
This Hubble view spans about 40,000
light-years at that estimated distance.
Of course,
Hickson Compact Groups also make for
rewarding viewing for Earth-bound astronomers
with more modest sized telescopes.
Authors & editors:
Robert Nemiroff
(MTU) &
Jerry Bonnell
(USRA)
NASA Web Site Statements, Warnings,
and Disclaimers
NASA Official: Jay Norris.
Specific
rights apply.
A service of:
LHEA at
NASA /
GSFC
& Michigan Tech. U.
