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One of the central themes both to science fiction and to real-life space progress was the drive to find and eventually travel to extrasolar plants. In recent years, constantly improving computer processing and better imaging technology have allowed scientists to at last confirm what many have long fantasized -- there's a wealth of planets outside our solar system.
From water bearing planets to ultra-hot ones, and even with a few that resembledlarger versions of Earth, extrasolar planets thus far have shown great variety. Most of these planets were detected using Doppler, or "wobble," technique to locate stars which were tugged at by the gravity of orbiting planets, leading to a wobble. Thus far, infrared images from the NASA Spitzer Space Telescope and spectral analysis of composition had provided us of our clearest picture of these worlds. However, the public has never seen a picture of an extrasolar planet -- until now.
The new images, developed by NASA and the Lawrence Livermore National Laboratory are the first-ever pictures taken from the visible spectrum, glimpsed by the Gemini North and Keck telescopes on the Mauna Kea mountaintop in Hawaii. British and American researchers snapped the first ever visible-light pictures of three extrasolar planets orbiting the star HR8799. HR8799 is about 1.5 times the size of the sun, located 130 light-years away in the Pegasus constellation. Observers can probably see this star through binoculars, scientists said.
To identify the planets, researchers compared images of the system, known to contain planets HF8799b, HF8799c, and HF8799d. In each image faint objects were detected, and by comparing images from over the years, it was confirmed that these were the planets in their expected positions and that they orbit their star in a counterclockwise direction.
NASA's Hubble Space Telescope at about the same time picked up images of a fourth planet, somewhat unexpectedly. The new planet, Fomalhaut b orbits the bright southern star Fomalhaut, part of the constellation Piscis Australis (Southern Fish) and is relatively massive -- about three times the size of Jupiter. The planet orbits 10.7 billion miles from its home star and is approximately 25 light-years from Earth.
Hubble astronomer Paul Kalas describes the challenge of obtaining the images, stating, "Our Hubble observations were incredibly demanding. Fomalhaut b is 1 billion times fainter than the star. We began this program in 2001, and our persistence finally paid off."
NASA and the Lawrence Livermore National Laboratory’s use of direct-imaging to "see" planets marks a new era in astronomy. Says Bruce Macintosh of the Lawrence Livermore National Laboratory in Livermore, California, "After all these years, it's amazing to have a picture showing not one but three planets. The discovery of the HR 8799 system is a crucial step on the road to the ultimate detection of another Earth."
While none of the planets were even remotely habitable, they are an important step towards imaging habitable worlds. Their discovery brings the total of known extrasolar planets to 326.
The photographs were published in two research studies in the American Association for the Advancement of Science's journal Science Express. They can be viewed here [1] [2].
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