- 2816 - STARS - seeing with new eyes? The Spitzer Space Telescope was launched in 2003. Its orbit follows the Earth, behind it by 56 million miles. Spitzer was viewing the Universe with infrared eyes. Our eyes can see red light at 700 nanometers. Yet when the wavelengths are stretched a little wider to 800 nanometers it becomes infrared and the light turns dark to our eyes.
--------------- 2816 - STARS - seeing with new eyes.?
- The night sky looks almost static, perfectly still and quiet. After a while you notice the Moon and Stars are moving. But, then you realize you are moving, they are sanding still. The Earth is doing the rotating.
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- So, stepping off the Earth things must be even more static. Nothing could be further from the truth. You can not imagine the violence that is out there. To understand it you must look at it with different eyes. This Review is helping you seeing with new eyes. Infrared eyes.
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- Space is anything but static. It is extremely violent. There would be 10 times as many stars in the sky if it were not for all this violence. Astronomers are starting to see it as they view the heavens in infrared light. Dust and gas block the visible light from ever reaching our eyes. The longer wavelengths of infrared light pass right through the dust without reflections. We see new sights.
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- This is somewhat like the big waves pass past the bobbing boat while the small waves would splash against the hull. The shorter wavelengths of visible light scatter on the dust creating a cloud we can not see through. We can only see the surface of those beautiful white water clouds in the daytime sky, we can not see through them.
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- Infrared telescopes see these new stellar nurseries as places of chaos and immense turbulence. Astronomers used to believe that stars were simply born when a giant gas cloud collapsed on itself until densities and temperatures at the center started a hydrogen fusion reaction.
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- These new eyes have shown us that stars are not born in isolation. The story of star birth that is much more complex has emerged. The gas clouds are spinning more rapidly as they collapse. The charged atoms in the spinning gas creates interstellar magnetic fields of immense strength.
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- The twisting magnetic fields launch powerful jets of gas along the axis of the disk and back into space. These jets are traveling out to 10 lightyears distance. When the jets encounter other gas clouds or other spinning proto-stars giant shock waves are produced.
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- With these new telescopes astronomers are creating a detailed picture of the interactions between infant stars and their chaotic environment. Our Sun floats in a cube 3 lightyears on a side. In a place like the Orion Nebula thousands of stars occupy the same space.
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- These high density clusters produce high-mass stars 10 to 100 times the mass of our Sun. These high-mass stars have short lives, only 10 million years, and they explode in giant supernovae. Their solar winds and ultraviolet radiation penetrate the neighboring space causing turmoil throughout the entire region.
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- The Spitzer Space Telescope was launched in 2003. Its orbit follows the Earth, behind it by 56 million miles. Spitzer was viewing the Universe with infrared eyes. Our eyes can see red light at 700 nanometers. Yet when the wavelengths are stretched a little wider to 800 nanometers it becomes infrared and the light turns dark to our eyes.
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- We can feel infrared as heat, but we can not see it. So, the things we see in the night sky are “hot” things emitting blue and white light. The Spitzer Infrared Telescope can see “cool” things like the stars and planets that are not hot enough to emit white light but still hot enough to emit infrared light.
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- The other miracle with infrared light is that it is “old” light. Due to the expansion of the Universe light that was emitted in the bright blue and ultraviolet wavelengths billions of years ago has gotten stretched out so it is now reaches us in the infrared wavelengths. Astronomers are able to study stars and galaxies that are 12.8 billion years old. Back then the Universe was only 14% its present size.
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- Astronomers have found over 4,000 planets orbiting several hundred nearby stars. Many of these planets are known as “ hot Jupiters” because they are large planets orbiting very close to their sun.
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- HD189733b is a planet 63 lightyears away. Its orbit is edge-on as seen from Earth. With each orbit the planet passes in front of the star. Spitzer can detect the slight drop in infrared light coming from the star when it later passes behind the star.
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- These studies have determined that the day and night side of the planet vary from 927 C to 649 C. The planet is locked in a single rotation around the star just as our Moon is locked in to a single rotation while orbiting around the Earth. The modest difference between day and night temperature suggest that winds on the surface redistribute the heat. Winds exceeding 1,000 miles per hour.
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- Spitzer completed a survey of our Milky Way viewing a 130 arc degree long strip one degree above and one degree below the plane of the galaxy. The data indicated the Milky way is a “barred” spiral galaxy. The “bar” is 28,000 lightyears long.
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- Stars orbit the galactic center in elliptical rather than in circular orbits. Astronomers thought the Milky Way had 4 spiral arms and named them Norma, Pereus, Sagittarius, and Scutum-Centaurus. This new data convinced astronomers that our galaxy had only 2 spiral arms, Scutum-Centaurus and Perseus.
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- Spitzer has discovered that at the center of most every galaxy is a Blackhole. Infrared detectors can not see a Blackhole directly. However, the accretion disk of Blackholes creates X-ray and ultraviolet emissions which in turn energizes other gases which emit infrared radiation Spitzer can see the infrared.
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- After 6 years in operation Spitzer ran out of helium coolant that ended its mission. Another infrared telescope is to take its place, the James Webb Space Telescope, to launch in 2021. Its capability will be 100 times greater that Spitzer’s.
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- All the data Spitzer has collected will easily keep astronomers busy for the several years. We live in interesting times seeing what has never been seen before. An optimist would proclaim that we live in the best of all worlds. A pessimist would fear that that is true.
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- September 8, 2020 1107 2816
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--------------------- --- September 9, 2020 --------------------------------------
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