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Organic molecules in the form of methane have been detected on a planet outside our solar system for the first time. The giant planet lies too close to its parent star for the methane to signal life, but the detection offers hope that astronomers will one day be able to analyse the atmospheres of Earth-like worlds.
Astronomers Mark Swain and Gautam Vasisht of Caltech in Pasadena, US, and Giovanna Tinetti of University College London, UK, used the Hubble Space Telescope to observe the giant planet HD 189733b, which is slightly more massive than Jupiter and lies 63 light years from Earth.

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Scientists have for the first time detected visible light from a planet orbiting a star other than the Sun.
Using a polarisation technique, the international team of astronomers led by Svetlana Berdyugina at the Swiss Federal Institute of Technology (ETH, Zurich), tracked the light reflected from the planet through its phases.
The star, called HD189733, is more than 60 light years from Earth in the constellation Vulpecula. The planet was first detected indirectly two years ago by Doppler spectroscopy, but light coming directly from it remained unobserved until the new polarisation technique filtered away most of the reflected sunlight. The technique reduced glare, enabling researchers to infer the size and details of the planet's orbit.

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An international team of astronomers, led by Professor Svetlana Berdyugina of ETH Zurichs Institute of Astronomy, has for the first time ever been able to detect and monitor the visible light that is scattered in the atmosphere of an exoplanet.
Employing techniques similar to how Polaroid sunglasses filter away reflected sunlight to reduce glare, the team of scientists were able to extract polarised light to enhance the faint reflected starlight glare from an exoplanet. As a result, the scientists could infer the size of its swollen atmosphere. They also directly traced the orbit of the planet, a feat of visualisation not possible using indirect methods.

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For the first time, the scattered light from a planet orbiting a distant star has been detected by an international team of astronomers led by Prof. Svetlana Berdyugina (ETH Zurich). Similar to how polaroid sunglasses filter away reflected sunlight to reduce glare, the scientists have used tricks with polarised light to enhance the faint reflected starlight "glare" from an extrasolar planet. This allowed them to trace directly the orbit of the planet and infer the size of its swollen atmosphere, in contrast to other exoplanets detected by various indirect methods.
The exoplanet circles a red dwarf star, called HD189733, in the constellation Vulpecula which lies about 60 light years from the Earth. The planet, known as HD189733b, was discovered two years ago via Doppler spectroscopy and photometric transits. It is so close to its central star that its atmosphere expands from the heat. Astronomers have, until now, never seen light reflected from an exoplanet although they deduce from other observations that this one probably resembles a "hot Jupiter". Unlike Jupiter, it orbits its star in a couple of days rather than the 12 years it takes Jupiter to make one orbit of the Sun.

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Using infrared images recorded by NASAs Spitzer Space Telescope, astronomers have created the first weather map of a planet outside our solar system. Only 60 light-years away in the constellation Vulpecula, planet HD 189733b is the closest known neighbour with an orbit that brings it directly between its star and Earth. The map was created from a composite of 278,528 images recorded by Spitzers infrared-array camera over a 33-hour stretch.

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A team of astronomers, led by Frederic Pont from the Geneva University Observatory in Switzerland, has detected for the first time strong evidence of hazes in the atmosphere of a planet orbiting a distant star. The new Hubble Space Telescope observations were made as the extrasolar planet, dubbed HD 189733b, passed in front of its parent star in an eclipse. As the light from the star briefly passes through the exoplanet's atmosphere, the gases in the atmosphere stamp their unique spectral fingerprints on the starlight. Where the scientists had expected to see the fingerprints of sodium and potassium, there were none; implying that high-level hazes (with an altitude of nearly 2,000 miles) are responsible for blocking the light from these elements.

Position (J2000):      R.A. 20h 00m 43s.72 Dec. +22° 42' 38".6

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The NASA/ESA Hubble Space Telescope has given astronomers a fascinating new insight into the atmosphere of a planet in orbit around another star. The observations provide evidence of the presence of hazes in the atmosphere of the planet HD 189733b.
A team of astronomers have used the NASA/ESA Hubble Space Telescope to detect, for the first time, strong evidence of hazes in the atmosphere of a planet orbiting a distant star. The discovery comes after extensive observations made recently with Hubbles Advanced Camera for Surveys (ACS).
The team, led by Frédéric Pont from the Geneva University Observatory in Switzerland, used Hubbles ACS to make the first detection of hazes in the atmosphere of the giant planet.


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University of Texas at Austin astronomer and Hubble Fellow Seth Redfield has used the Hobby-Eberly Telescope (HET) at McDonald Observatory to make the first ground-based detection of the atmosphere of a planet outside our solar system. This research has been accepted for publication in an upcoming issue of Astrophysical Journal Letters.

Its a remarkable pioneering discovery - McDonald Observatory Director David L. Lambert.

The work is an incremental step in finding life in the universe, falling between the initial detections of planets around other stars (known as extra-solar planets or exoplanets), and the anticipated discovery of planets similar to Earth.

What we all want to find is a planet with an Earth-like atmosphere - Seth Redfield .

The planet Redfield studied orbits HD189733, a star about 63 light-years away in the constellation Vulpecula, the little fox. But its not like Earth. The planet is 20 percent more massive than Jupiter, and orbits very close to its parent star (more than 10 times closer than Mercury is to our Sun).
From Earths line of sight, the planet passes directly in front of the star on each orbit. That means this planet, HD189733b, is whats known as a transiting extra-solar planet. It was this transit property that allowed the planets discovery in 2004 by Francois Bouchy of Frances Laboratoire dAstrophysique de Marseille, and the detection of its atmosphere in 2007 by Redfield.

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Title: Primary transit of the planet HD189733b at 3.6 and 5.8 microns
Authors: J.P. Beaulieu, S. Carey, I. Ribas, G. Tinetti

The hot Jupiter HD 189733b was observed during its primary transit using the Infrared Array Camera on the Spitzer Space Telescope. The transit depths were measured simultaneously at 3.6 and 5.8 microns. Our analysis yields values of 2.356 ± 0.019 % and 2.436 ± 0.020 % at 3.6 and 5.8 microns respectively, for a uniform source. We estimated the contribution of the limb-darkening and star-spot effects on the final results. We concluded that although the limb darkening increases by ~0.02-0.03 % the transit depths, and the differential effects between the two IRAC bands is even smaller, 0.01 %. Furthermore, the host star is known to be an active spotted K star with observed photometric modulation. If we adopt an extreme model of 20 % coverage with spots 1000K cooler of the star surface, it will make the observed transits shallower by 0.19 and 0.18 %. The difference between the two bands will be only of 0.01 %, in the opposite direction to the limb darkening correction. If the transit depth is affected by limb darkening and spots, the differential effects between the 3.6 and 5.8 microns bands are very small. The differential transit depths at 3.6 and 5.8 microns and the recent one published by Knutson et al.(2007) at 8 microns are in agreement with the presence of water vapour in the upper atmosphere of the planet. This is the companion paper to Tinetti et al. (2007b), where the detailed atmosphere models are presented.

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