A new, lightweight planet has been discovered orbiting a star 450 light-years away in the constellation Lacerta. This unusual planet is larger than Jupiter, but it has only half its mass; astronomers estimate it has the same density as cork. The planet, named HAT-P-1, orbits its host star every 4.5 days. A network of automated telescopes detected how the planet dims its parent star by 1.5% when it passes in between the star and the Earth. Why this planet is so swollen is still a mystery to astronomers.
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Identifying Planets with Life
Telescope technology is advancing quickly, as larger and larger instruments are getting built. Eventually, an observatory will be built capable of resolving Earth-sized worlds orbiting other stars. If there’s life there, will we recognize it? Researchers from Harvard-Smithsonian Center for Astrophysics and NASA have developed a list of epochs in Earth’s atmosphere’s history that could be visible through this instrument; from the earliest times that life emerged to our current, oxygen/nitrogen-abundant atmosphere.
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Network of Small Telescopes Find a Big Planet
A network of amateur astronomers has discovered an extrasolar planet located 500 light years away. This incredible discovery was made using a technique that measures the brightness of thousands of stars, watching for a periodic dimming. In this case, the Jupiter-sized planet, TrES-2, orbits its host star every 2.5 days, dimming it by 1.5%. Although the planet was discovered by a 10cm telescope, followup observations were made using the 10 metre W.M. Keck Observatory on Mauna Kea in Hawaii.
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Earth-Sized Planets are Probably Common
Of the many extrasolar planetary systems discovered so far, more than a third could contain Earth-like planets. This is according to a new study by scientists associated with NASA’s Center for Astrobiology. It was originally thought that Jupiter-sized planets should clear out their star systems as they form, but some new calculations show that they actually promote the formation of rocky planets – and even help pull in icy objects that deliver water to the inner planets.
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Giant Planet or Failed Star?
The Hubble Space Telescope has helped astronomers uncover an object right at the dividing line between stars and planets. The object, known as CHXR 73 B, weighs in at about 12 times the mass of Jupiter, and orbits a larger red dwarf star. The two objects are separated by 200 times the distance of the Earth to the Sun, so astronomers don’t think they both formed out of the same disk of gas and dust.
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Astrophoto: Stellar Nursery NGC 7129 by Bob Allevo
Prior to 1957, virtually all photographs of the sky were produced as monochrome, black and white images. In that year, Ansco, once the world’s largest supplier of professional films, papers, and photo chemicals, introduced Super Anscochrome and over the next twenty-four months, full color images of the heavens were being released by the larger observatories. Over the years technology has improved and the colors captured in astronomical imagery have become more vivid and meaningful. For example, the hues seen in the accompanying picture represent not only this scene’s true-to-nature pallet, but it also reveals what you are looking at, too.
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Hubble Finds an Exoplanet’s Parent Star
When a star flared briefly, astronomers knew it was because a dimmer star had passed directly in front, acting as a lens with its gravity to focus light. Unfortunately, they couldn’t find the star. This was important, because the brief microlensing event also turned up the fact that this lensing star has a planet. Astronomers have used the power of the Hubble Space Telescope to find this dim star two years after the lensing event. Identifying the star is critical, because it allows astronomers to measure its unique characteristics, such as mass, temperature and composition.
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Twin Planemos Discovered
Astronomers have turned up plenty of extrasolar planets, but a newly discovered binary pair of planets is quite the find. The system consists of a 7-Jupiter mass planet and a 14-Jupiter mass planet… but no star. These planets – or “planemos” – just orbit each other. Their discovery challenges the current theory that planets are thought to form out of the disks of gas and dust that surround newborn stars.
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Earth-Sized Planets Could Be Nearby
Nearly all of the extrasolar planets discovered so far have been huge, Jupiter-sized and above. The question is: could smaller, Earth-sized planets last in the same star systems? Researchers created a simulation where tiny planets were put into the same system as larger planets to see if they could gather enough material to become as large as the Earth. They found that one nearby system – 55 Cancri – could have formed terrestrial planets, with substantial water in the habitable zone.
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Squadrons of Planet Hunters Could Find Life
The Hubble Space Telescope demonstrated that the best viewing is outside the Earth’s atmosphere. Over the years, a series of new telescopes have been lofted into space, and expanded this view into other wavelengths: Spitzer, Chandra, Compton, etc. Next up is the James Webb Space Telescope, with a mirror 6 times larger than Hubble, due for launch in 2013. But these observatories will pale in comparison when squadrons of space telescopes reach orbit. Both NASA and ESA are working on next generation space-based interferometers. They could answer one of the most fundamental questions of science: is there other life in the Universe?
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