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The galaxy Messier 74 lies at a distance over 30 million light years.
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In the latest image from the NASA/ESA Hubble Space Telescope
the enormous swirls of this stunning spiral galaxy
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arc across space adorned with glowing pink regions of hydrogen
gas and lit by the pale blue light of millions of newly formed stars.
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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 Doctor J a.k.a. Dr Joe Liske.
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Welcome to the Hubblecast!
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Over the course of its seventeen years in space the Hubble
Space Telescope has imaged literally thousands of galaxies.
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However this latest image from the orbiting space observatory
is clearly a red hot candidate for being one of the finest images of a galaxy ever seen.
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This striking image from Hubble shows Messier 74 a spiral galaxy
located about 32 million light years away from Earth.
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In the new image, Hubble reveals the light from billions of stars
in the spiral arms of this stunning galaxy,
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laced with delicate tendrils of dust silhouetted against the swirling arms.
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This galaxy (also known as NGC 628) was first observed in 1780 by a
French astronomer called Pierre Méchain
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who was searching the sky for objects that might be comets.
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Soon after he discovered the galaxy, Méchain told his good friend
Charles Messier, who then listed it as M74 in his now famous catalogue of deep sky objects.
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Of all the objects in Messier’s catalogue, number 74 has the lowest
surface brightness
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and is so difficult for amateur astronomers to spot through a telescope
that it has been given the nickname “The Phantom Galaxy”.
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The stunning new image also shows a sprinkling of bright red regions
decorating the spiral arms.
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These are vast, relatively short-lived, clouds of hydrogen gas which
glow due to the strong radiation from hot, young stars.
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Astronomers call these clouds HII regions.
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The really bright stars in the image are actually foreground stars
located within our own Milky Way galaxy.
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They are much closer and are not part of M74 behind them.
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Hubble’s image also shows an intricate network of dust lanes weaving
through the galaxy’s spiral arms.
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These dusty swirls have partly been created by previous generations of
stars
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which seeded the galaxy with newly formed chemical elements when they
died as supernovae.
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In fact two such supernovae have been seen to explode in M74 in recent
years.
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In this image of Messier 74 we can see the blue light from millions of
young blue stars in the two main spiral arms of the galaxy.
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These spiral arms are not actually static ‘arms’ like spokes on a wheel.
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They are in fact density waves and move around the galaxy’s disc compressing gas –
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just as sound waves compress the air on Earth – creating new generations
of young blue stars.
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Because of the elegant symmetry of its spiral arms astronomers call this
a ‘grand design spiral’.
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Messier 74 bears a strong resemblance to another ‘grand design spiral’,
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Messier 51, the Whirlpool Galaxy in the constellation of Canes Venatici
the Hunting Dogs.
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Messier 74 is arguably one of the most photogenic galaxies Hubble has
ever observed.
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With its myriad of stars and delicate dust lanes it is a place of serene
beauty and grandeur on a truly galactic scale.
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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 at the European Southern
Observatory in Germany.
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The Hubble mission is a project of international cooperation between
NASA and the European Space Agency.
