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Hubble has delivered
an unrivalled snapshot

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of nearby barred spiral galaxy
NGC 1672.

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This remarkable image provides
a high definition view

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of the galaxy's large bar,
its field of star forming clouds

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and its dark bands
of interstellar dust.

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This is the Hubblecast.

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News and images from the
NASA / ESA Hubble Space Telescope.

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Travelling through time and space
with our host, Dr. J

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EPISODE 2: Galaxy bars
and supermassive black holes
a.k.a. Dr. Joe Liske.

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Welcome to the Hubblecast.

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Now, when we look around us in the
universe with powerful telescopes

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essentially all the light we see comes
to us from billions and billions of stars.

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And these stars are gathered
together in galaxies.

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So, galaxies are essentially
just huge collections

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of stars, gas and dust. And they
come in an enormous variety

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of different shapes and sizes.

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Now, today I'd like to talk to you
about one particular galaxy.

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And that's NGC 1672, located in
the Dorado or Swordfish constellation.

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Now, here is a spectacular
brand new image

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from the NASA / ESA
Hubble Space Telescope.

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As you can see straight away
it is a spiral galaxy.

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In fact, it is a prototypical example
of a so called barred spiral galaxy.

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and it is viewed nearly faced on.

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Barred spirals differ from normal
spiral galaxies in that their arms

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do not twist all the way
into the center.

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Instead they're attached at
two ends of a straight bar of stars.

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Four principal arms
extend from the center

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and give NGC 1672 a rather
symmetric appearance.

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Eye-catching dust lanes
extend away from the nucleus

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and follow the inner sides
of the spiral arms.

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Hot young blue stars are seen
in vigorous star forming clusters

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in the galaxy's spiral arms.

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Delicate curtains of dust
partially obscure the light

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of the stars behind them
and colour them red.

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NGC 1672 is almost like
a sister galaxy

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to our own galactic home,
the Milky Way.

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The Milky Way also has
a huge bar of stars

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which was recently seen in great
detail by the infrared eyes

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of the NASA Spitzer Space Telescope.

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The two galaxies
also have in common

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that their spiral arms are
quite loosely wrapped.

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Now, astronomers believe
that barred spiral galaxies

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have unique mechanisms that
channels gas from the disk

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inwards towards
the center of the galaxy.

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And it is thought that this gas
also makes a really good meal

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for a putative supermassive
black hole that seats at the center.

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Moreover, bars are thought
to be quite short lived.

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So, the big question is:
will non-barred spiral galaxies

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develop a bar in the future or
have they hosted a bar in the past

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that has since died out.

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Behind the galaxy, several
more distant galaxies are seen.

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They are coloured caramel by
the dust in NGC 1672.

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Also seen in the image
are a few bright much closer

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foreground stars from
our own Milky Way.

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Astronomers are still puzzled
about how bars actually form.

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They could be the result of
instabilities in the disk

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that harbours the spiral arms,
or they could develop

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in the aftermath of galactic collisions.

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In any case, the formation and
evolution of bars

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is still a matter of debate.

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This is Dr. J
signing off for the Hubblecast.

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Once again, nature has surprised us
beyond our wildest imagination...

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Hubblecast is produced
by ESA / Hubble

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at the European
Southern Observatory in Germany.

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The Hubble mission is a project
of international cooperation

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between NASA and
the European Space Agency.