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Hubble Spies NGC 4394
Barred spiral galaxy
RA 12h 25m 55.75s Dec 18° 12' 48.96"
55 million light years
3.5' x 3.3'
3.05 x 3.29 arcminutes
North is 0.2° left of vertica
ESA/Hubble & NASA
2 May 2, 2016
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ABOUT THIS IMAGE:
Discovered in 1784 by the German-British astronomer William Herschel, NGC 4394 is a barred spiral galaxy situated about 55 million light-years from Earth. The galaxy lies in the constellation of Coma Berenices (Berenice's Hair), and is considered to be a member of the Virgo Cluster.
NGC 4394 is the archetypal barred spiral galaxy, with bright spiral arms emerging from the ends of a bar that cuts through the galaxy's central bulge. These arms are peppered with young blue stars, dark filaments of cosmic dust, and bright, fuzzy regions of active star formation. At the center of NGC 4394 lies a region of ionized gas known as a LINER. LINERs are active regions that display a characteristic set of emission lines in their spectra- mostly weakly ionized atoms of oxygen, nitrogen and sulphur.
LINER galaxies are relatively common, it's still unclear where the energy
comes from to ionize the gas. In most cases it is thought to be the influence
of a black hole at the center of the galaxy, but it could also be the
result of a high level of star formation. In the case of NGC 4394, it
is likely that gravitational interaction with a nearby neighbor has caused
gas to flow into the galaxy's central region, providing a new reservoir
of material to fuel the black hole or to make new stars.