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Mindblowing.

 

http://www.hubblesite.org/newscenter/archive/releases/2009/25/image/

 

hs-2009-25-l-large_web.jpg

 

hs-2009-25-b-large_web.jpg

 

This celestial object looks like a delicate butterfly. But it is far from serene.

 

What resemble dainty butterfly wings are actually roiling cauldrons of gas heated to more than 36,000 degrees Fahrenheit. The gas is tearing across space at more than 600,000 miles an hour—fast enough to travel from Earth to the Moon in 24 minutes!

 

A dying star that was once about five times the mass of the Sun is at the center of this fury. It has ejected its envelope of gases and is now unleashing a stream of ultraviolet radiation that is making the cast-off material glow. This object is an example of a planetary nebula, so-named because many of them have a round appearance resembling that of a planet when viewed through a small telescope.

 

The Wide Field Camera 3 (WFC3), a new camera aboard NASA's Hubble Space Telescope, snapped this image of the planetary nebula, catalogued as NGC 6302, but more popularly called the Bug Nebula or the Butterfly Nebula. WFC3 was installed by NASA astronauts in May 2009, during the servicing mission to upgrade and repair the 19-year-old Hubble telescope.

 

NGC 6302 lies within our Milky Way galaxy, roughly 3,800 light-years away in the constellation Scorpius. The glowing gas is the star's outer layers, expelled over about 2,200 years. The "butterfly" stretches for more than two light-years, which is about half the distance from the Sun to the nearest star, Alpha Centauri.

 

The central star itself cannot be seen, because it is hidden within a doughnut-shaped ring of dust, which appears as a dark band pinching the nebula in the center. The thick dust belt constricts the star's outflow, creating the classic "bipolar" or hourglass shape displayed by some planetary nebulae.

 

The star's surface temperature is estimated to be about 400,000 degrees Fahrenheit, making it one of the hottest known stars in our galaxy. Spectroscopic observations made with ground-based telescopes show that the gas is roughly 36,000 degrees Fahrenheit, which is unusually hot compared to a typical planetary nebula.

 

The WFC3 image reveals a complex history of ejections from the star. The star first evolved into a huge red-giant star, with a diameter of about 1,000 times that of our Sun. It then lost its extended outer layers. Some of this gas was cast off from its equator at a relatively slow speed, perhaps as low as 20,000 miles an hour, creating the doughnut-shaped ring. Other gas was ejected perpendicular to the ring at higher speeds, producing the elongated "wings" of the butterfly-shaped structure. Later, as the central star heated up, a much faster stellar wind, a stream of charged particles traveling at more than 2 million miles an hour, plowed through the existing wing-shaped structure, further modifying its shape.

 

The image also shows numerous finger-like projections pointing back to the star, which may mark denser blobs in the outflow that have resisted the pressure from the stellar wind.

 

The nebula's reddish outer edges are largely due to light emitted by nitrogen, which marks the coolest gas visible in the picture. WFC3 is equipped with a wide variety of filters that isolate light emitted by various chemical elements, allowing astronomers to infer properties of the nebular gas, such as its temperature, density, and composition.

 

The white-colored regions are areas where light is emitted by sulfur. These are regions where fast-moving gas overtakes and collides with slow-moving gas that left the star at an earlier time, producing shock waves in the gas (the bright white edges on the sides facing the central star). The white blob with the crisp edge at upper right is an example of one of those shock waves.

 

NGC 6302 was imaged on July 27, 2009, with Hubble's Wide Field Camera 3 in ultraviolet and visible light. Filters that isolate emissions from oxygen, helium, hydrogen, nitrogen, and sulfur from the planetary nebula were used to create this composite image.

 

These Hubble observations of the planetary nebula NGC 6302 are part of the Hubble Servicing Mission 4 Early Release Observations.

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sometimes they will try to approximate visible light, but generally, the colors are false and the brightness levels are false. they take the most interesting chunks of the spectrum (infrared, xray, etc) and represent them as the red, green, and blue channels of the image.

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oh and regarding colour:

 

There are no "natural color" cameras aboard the Hubble and never have been. The optical cameras on board have all been digital CCD cameras, which take images as grayscale pixels.

 

Sometimes the color is as natural as possible. However, the color given to the images is not just "artistic embellishment." The images are, indeed, downloaded as black and white, and color is added for a number of different reasons -- for example, to show the dispersion detail of chemical elements and highlight features so subdued that the human eye cannot see them.

 

more info at http://www.hubblesite.org/gallery/behind_the_pictures/meaning_of_color/index.shtml

also http://en.wikipedia.org/wiki/Bayer_filter

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these things are not technically there am I correct? I mean, the hubble is collecting light for the image but the light is just arriving here. Light takes time to travel so this things we are seeing are snap shots from billions to millions of years. We don't really know what is out there presently. Am I right? Im not sure, but I think I am

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you are right, the information that reaches the lens of the hubble in the form of photons has taken millions of years to reach there - so essentially, the nearer something is, the newer and potentially brighter it is. also worth bearing in mind that the hubble's exposure time is looooooooong. so most of these things are invisible at normal wavelengths/exposure times/colouring parameters.

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Guest ezkerraldean

these things are not technically there am I correct? I mean, the hubble is collecting light for the image but the light is just arriving here. Light takes time to travel so this things we are seeing are snap shots from billions to millions of years. We don't really know what is out there presently. Am I right? Im not sure, but I think I am

 

most of this stuff will still be there at present. all the images of pretty nebulas etc are of objects in our own galaxy, limiting their distance to about a hundred thousand light years if i remember my shit. planetary nebulas though (like the second pic) actively expand, and only last a few tens of thousands of years before becoming too diffuse to distinguish, so any that we see today might not actually exist anymore.

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