Theme: Planetary Nebulas

 

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Text, Viewspace. The show will continue in 15 seconds. Coming up: Discover the beauty of planetary nebulas. 

 

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The text appears on a background of stars which move slowly towards and past us. 

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A close-up of the Sun's surface. Gases bubble and burn intense orange and yellow.

 

Text, Our Sun will not live forever.

 

Someday, billions of years from now, the Sun will run out of the nuclear fuel that powers it.

 

The Sun in the distance.

 

Text, As the Sun's core contracts and grows hotter, the Sun's outer layers will swell.

 

The Sun grows, darkens and turns the Earth red.

 

Text, Our star will turn into a "red giant."

 

The Sun will puff up so much that it will engulf Mercury and Venus, and perhaps even Earth.

 

The enlarged Sun engulfs and burns up the red Earth.

 

Gases expand in a sphere in space.

 

Text, Eventually, the Sun's outer layers will float away, forming clouds of gas and dust around the dying star.

 

The gases, which glow red, orange, blue, and purple, spread out in waves.

 

Text, Ultraviolet energy from the Sun's hot core will heat the gas and cause it to glow.

 

Text, Eventually, the Sun will cast off its outer layers, forming a planetary nebula. A white dwarf, the hot, dense core of the Sun that glows white-hot, will be left behind.

 

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 Top left, a black and white picture of a minotaur. Top right, a color picture of a nebula. 

Text, MYTH versus REALITY 

Myth side 

Text, Planetary nebulae are related to planets. 

Reality side 

Text, Planetary nebulae are actually the gaseous remains of dead or dying medium-sized stars that have blown away their outer layers. When they were first observed with small telescopes, these cosmic clouds looked to astronomers like planets. Early observers called them planetary nebulae, and the name stuck. 

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 A two-lobed pink and orange nebula. 

Text, PLANETARY NEBULA NGC 2440. This planetary nebula is the colorful "last hurrah" of a star like the Sun. The dying star has cast off its outer layers of gas and is now much smaller than the Sun. 

Ultraviolet light from the star's hot core heats the gas and makes it glow. 

The nebula's bow-tie shape suggests the star might have released its gas in multiple bursts and in different directions. 

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 Top left, a black and white picture of a minotaur. Top right, a color picture of a nebula. 

Text, MYTH versus REALITY 

Myth side 

Text, All planetary nebulae are round. 

Reality side 

Text, Planetary nebulae come in a variety of shapes. Some are spherical, but others are elongated. Some have two or more lobes, while others are an intricate array of gaseous shells and jets. Like celestial snowflakes, no two planetary nebulae are exactly alike. 

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 at-a-GLANCE. Shapes of planetary nebulae. 

4 different-shaped nebulae bloom 

Planetary nebulae have many different shapes. 

But all planetary nebulae form during the death of a Sun-like star. 

So why do they have different shapes? 

Shapes of planetary nebulae: Round, elliptical, bipolar, and complex 

Round planetary nebulae probably form when stars eject their outer layers, more or less evenly in all directions. 

Stellar winds, streams of particles from the star, might blow stronger in one direction, making some planetary nebulae elongated or "elliptical." 

Bipolar planetary nebulae might be created by a star that has an unseen companion. 

The two stars orbit each other. Near the end of its life, the Sun-like star swells, "swallowing" the smaller star! 

This makes the big star spin faster and it throws off a ring of gas and dust. 

The ring forces stellar winds into jets above and below the ring. 

Planetary nebulae with complex shapes might be made by stars with wobbling jets. 

These wandering jets funnel material away from the star in various directions rather like a loose, rotating garden sprinkler. 

The jets might be made to wobble by the gravitational tug of a second star. 

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A pink and red nebula in the shape of a butterfly.

 

Text, PLANETARY NEBULA N.G.C. 6302. Sometimes called the Bug Nebula, this planetary nebula turns into a cosmic butterfly when viewed with the Hubble Space Telescope.

 

The star that created this nebula is surrounded by a donut-shaped ring of dust.

 

The dust ring constricts the outflow of gas to two opposing directions, forming the beautiful "butterfly wings."

 

The gas in the wings is expanding through space at more than 600,000 miles an hour -- fast enough to travel from Earth to the Moon in 24 minutes.

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Text, Sculptures in the sky. A bubble of gas expands into space, one of the thousands of planetary nebulae known within our milky way galaxy. . A pale white ring of gas in a dark starry sky.

 

A nebula is a cloud of gas and dust. Image of N G C 7009, an oblong round cloud nebula. Text, Early astronomers called some of these clouds planetary nebulae because they looked like planets. The planet saturn, a sphere with rings around it, a slightly similar shape. Text, but planetary nebulae have nothing to do with planets. 6 different nebulae each with a different shape and color pattern, some bright red or orange and others blue green and purple. Text, they are shells of gas ejected by dying stars. From earth most planetary nebulae look tiny. An observatory under a night sky looking up at a tiny point of light. An animation of a cylindrical satellite telescope passing high over earth. Text, Orbiting above earth's atmosphere Nasa's hubble space telescope can see amazing details in planetary nebulae.

 

An image of the cat's eye nebula, a blurry view from ground then a sharp view from Hubble, 2 bright yellow green round clouds with a bright point in the center and rimmed with red.

 

The ring nebula, seen from the ground, a blurry ring-shaped cloud, resolves into a magnificent barrel of gas cast off by a dying star thousands of years ago.

 

In this planetary nebula, called the Spirograph, Hubble has revealed complex textures never before seen. A round nebula with a bright purple center criss-crossed by many overlapping lines in a pattern. Text, tattered streams of gas radiate from the center of this planetary nebula which looks like a giant eye. This stellar relic is nicknamed clownface nebula; it resembles a face surrounded by curly hair. A bright round orange nebula with a ring of fluffy clouds around it. Text, in the outer ring comet-like tails stream away from the central dying star.

 

The face of the clown looks like a ball of twine, but is really a bubble of gas and dust being blown into space by a strong wind from the star.

 

A mere 650 light years away the helix nebula is one of the closest planetary nebula to earth. An eye shaped nebula with a clear blue center and magenta clouds at the edges. The view from Hubble, a more complex and detailed view with layers of orangeish clouds. Text, Because the helix nebula is so close Hubble can see fine details. Zoom in on the edge of the center of the nebula. Text, Thousands of tadpole-shaped cometary knots surround the dying star. Unlike comets in our solar system, these knots are billions of miles across.

 

An image of a diffused purplish cloud filled with reddish stars. Text, peering into the Large Magellanic Cloud, 160,000 light years away, Hubble has delivered some of the best views of planetary nebulae in another galaxy. Images of small green and purple galaxies. Text, these nebulae are 50 times farther away than the ones we study in our own galaxy.

 

Like those in our galaxy, these planetary nebulae show a range of shapes, bipolar, round, complex, elliptical.

 

Unlike planetaries in our galaxy, these are all about the same distance from us.

 

Because of this, astronomers can directly compare the size and brightness of these planetary nebulae.

 

With these observations, Hubble helps us better understand how planetary nebulae form and evolve.

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 A nebula with several gaseous spheres. 

Text, CAT'S EYE NEBULA. The Cat's Eye Nebula is one of the most complex planetary nebulae ever seen. 

Hubble Space Telescope images reveal multiple shells of gas and dust that were probably ejected by the star early in the nebula's formation. 

Later, the dying star ejected symmetric lobes of gas in opposite directions. 

A pair of wobbling jets might have pushed away some of the gas into two swirling tendrils on either end.