
Science Resources RSS Feeds
|
 |
 |
 |
Polarization technique focuses limelight
December 27, 2007
An international team of astronomers, led by Professor Svetlana Berdyugina of ETH Zurich's 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 polarized 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 visualization not possible using indirect methods. Hot Jupiter
The transiting exoplanet under study circles the dwarf star HD189733 in the constellation Vulpecula and lies more than 60 light years from the earth. Known as HD189733b, this exoplanet was discovered two years ago via Doppler spec-troscopy. HD189733b is so close to its parent star that its atmosphere expands from the heat. Until now, astronomers have never seen light reflected from an exoplanet, although they have deduced from other observations that HD189733b probably resembles a 'hot Jupiter' - a planet orbiting extremely closely to its parent star. Unlike Jupiter, however, HD189733b orbits its star in a couple of days rather than the 12 years it takes Jupiter to make one orbit of the sun.
Two half-moon phases
The international team, consisting of Svetlana Berdyugina, Dominique Fluri (ETH Zurich), Andrei Berdyugin and Vilppu Piirola (Tuorla Observatory, Finland), used the 60cm KVA telescope by remote control. The telescope, which belongs to the Royal Swedish Academy of Science, is located at La Palma, Spain and was modernised by scientists in Finland. The researchers obtained polarimetric measurements of the star and its planet. They discovered that polarization peaks near the moments when half of the planet is illuminated by the star as seen from the earth. Such events occur twice during the orbit, similar to half-moon phases.
The polarization indicates that the scattering atmosphere is considerably larger (>30%) than the opaque body of the planet seen during transits and most probably consists of particles smaller than half a micron, for example atoms, molecules, tiny dust grains or perhaps water vapour, which was recently sug-gested to be present in the atmosphere. Such particles effectively scatter blue light - in exactly the same scattering process that creates the blue sky of the earth's atmosphere. The scientists were also able for the first time to recover the orientation of the planet's orbit and trace its motion in the sky.
"The polarimetric detection of the reflected light from exoplanets opens new and vast opportunities for exploring physical conditions in their atmospheres", Pro-fessor Svetlana Berdyugina said. "In addition, more can be learned about radii and true masses, and thus the densities of non-transiting planets."
ETH Zurich/Swiss Federal Institute of Technology
|
 |
Related Exoplanet Current Events and Exoplanet News Articles Exoplanet Current Events and Exoplanet News RSS Exoplanets clue to sun's curious chemistry "For almost 10 years we have tried to find out what distinguishes stars with planetary systems from their barren cousins," says Garik Israelian, lead author of a paper appearing this week in the journal Nature. "We have now found that the amount of lithium in Sun-like stars depends on whether or not they have planets."
32 new exoplanets found The latest batch of exoplanets announced today comprises no less than 32 new discoveries. Including these new results, data from HARPS have led to the discovery of more than 75 exoplanets in 30 different planetary systems.
Simulation suggests rocky exoplanet has bizarre atmosphere So accustomed are we to the sunshine, rain, fog and snow of our home planet that we find it next to impossible to imagine a different atmosphere and other forms of precipitation.
First solid evidence for a rocky exoplanet The longest set of HARPS measurements ever made has firmly established the nature of the smallest and fastest-orbiting exoplanet known, CoRoT-7b, revealing its mass as five times that of Earth's.
Seeing the Cosmos Through NASA's Spitzer Space Telescope has taken its first shots of the cosmos since warming up and starting its second career. The infrared telescope ran out of coolant on May 15, 2009, more than five-and-half-years after launch, and has since warmed to a still-frosty 30 Kelvin (about minus 406 Fahrenheit).
New technique could find water on Earth-like planets orbiting distant suns Since the early 1990s astronomers have discovered more than 300 planets orbiting stars other than our sun, nearly all of them gas giants like Jupiter.
Lightest exoplanet yet discovered Well-known exoplanet researcher Michel Mayor today announced the discovery of the lightest exoplanet found so far. The planet, "e", in the famous system Gliese 581, is only about twice the mass of our Earth.
COROT finds exoplanet orbiting Sun-like star A team of European scientists working with COROT have discovered an exoplanet orbiting a star slightly more massive than the Sun. After just 555 days in orbit, the mission has now observed more than 50 000 stars and is adding significantly to our knowledge of the fundamental workings of stars.
The Drifting Star By studying in great detail the 'ringing' of a planet-harbouring star, a team of astronomers using ESO's 3.6-m telescope have shown that it must have drifted away from the metal-rich Hyades cluster. This discovery has implications for theories of star and planet formation, and for the dynamics of our Milky Way.
New rocky planet found in constellation Leo Spanish and UCL (University College London) scientists have discovered a possible terrestrial-type planet orbiting a star in the constellation of Leo. The new planet, which lies at a distance of 30 light years from the Earth, has a mass five times that of our planet but is the smallest found to date. One full day on the new planet would be equivalent to three weeks on Earth. More Exoplanet Current Events and Exoplanet News Articles
|
 |

|
Exoplanets: Detection, Formation, Properties, Habitability (Springer Praxis Books / Astronomy and Planetary Sciences)
by John W. Mason (Author), John W. Mason (Editor)
This edited, multi-author volume will be an invaluable introduction and reference to all key aspects in the field of exoplanet research. The reviews cover: Detection methods and properties of known exoplanets, Detection of extrasolar planets by gravitational microlensing. The formation and evolution of terrestrial planets in protoplanetary and debris disks. The brown dwarf-exoplanet connection. Formation, migration mechanisms and properties of hot Jupiters. Dynamics of multiple exoplanet systems. Doppler exoplanet surveys. Searching for exoplanets in the stellar graveyard. Formation and habitability of extra solar planets in multiple star systems. Exoplanet habitats and the possibilities for life. Moons of exoplanets: habitats for life. Contributing authors: Rory Barnes...
|

|
New Worlds in the Cosmos: The Discovery of Exoplanets
by Michel Mayor (Author), Pierre-Yves Frei (Author), Boud Roukema (Translator)
With the discovery in 1995 of the first planet orbiting another star, we now realize that planets are not unique to our own Solar System. For centuries, humanity has wondered whether we are alone in the Universe. We are now finally one step closer to knowing the answer. The quest for exoplanets is an exciting one because it holds the possibility that one day we might find life elsewhere in the Universe, born in the light of another sun. Written from the perspective of one of the pioneers of this scientific adventure, this exciting account describes the development of the modern observing technique that has enabled astronomers to find so many planets orbiting around other stars. It reveals the wealth of new planets that have now been discovered outside our Solar System, and the meaning of...
|

|
Flight Of The Outcast Owl (Original Mix)
Exoplanet (Primary Contributor)
|

|
Artist's Impression of a Unique Type of Exoplanet Photographic Poster Print by Stocktrek Images, 24x24
by Art.com
Art.com is the world's largest retailer of art prints, posters, photographs, and framed artwork. With our huge selection of over 400,000 prints, you'll easily find the perfect piece for your home, office, or classroom. Our art is printed on quality paper. When you order framed artwork, the piece is built by our team of in-house professionals. Visit our Amazon store today at www.amazon.com/artdotcom to find Special Offers and search for products based on 'Artist Name' and 'Subject Categories' such as Movie, Music, Vintage, TV, Children, Travel, Kitchen, Museum Art, Animals, Floral, Motivational, and Sports. Art.com is dedicated to providing you with high quality products and service by offering you 100% satisfaction guaranteed. We ship internationally to over 80 countries. Decorate your...
|

|
Wandering Stars: About Planets And Exo-planets, An Introductory Notebook
by George H. A. Cole (Author)
The space vehicle spectaculars of recent years have been revealing the full scope and beauty of our own solar system but have also shown that a growing number of other stars too have planetary bodies orbiting around them. The study of these systems is just beginning. It seems that our galaxy contains untold numbers of planets, and presumably other galaxies will be similar to our own. Our solar system contains life, on Earth: do others as well? Such questions excite modern planetary scientists and astro-biologists. This situation is a far cry from ancient times when the five planets that can be seen from Earth without a telescope were called the "wandering stars". This notebook-cum-workbook provides an introduction to those profound and still-developing modern studies. Written by an...
|
|
|
Dynamics of Small Solar System Bodies and Exoplanets (Lecture Notes in Physics)
by Rudolf Dvorak (Editor), Jean J. Souchay (Editor)
This book offers an up-to-date overview of current research on Dynamics of Small Solar System Bodies and Exoplanets. In course-tested extensive chapters the authors cover topics of theoretical celestial mechanics, physics and dynamics of asteroids, comets, stability of exoplanets and numerical integration codes applied in dynamical astronomy.
|

|
Metaphor (Original Mix)
Exoplanet (Primary Contributor)
|

|
It's Astronomical: Exoplanets
by Andrew Bridges (Author), Erin Hunter (Illustrator)
The Universe doesn't end with us. There are countless other suns out theremany, many, many, just like our own. And orbiting some of those stars are other planetsso far over 200 exoplanets have been discovered since 1995! Noted science writer Andrew Bridges draws on the latest findings from powerful telescopes in space and on Earth to describe how astronomers detect planets beyond our solar system, and what they're learning about those exoplanets and the stars they orbit. This book contains dozens of full-color photographs and illustrations.
|

|
Gas-Giant Exoplanet Transiting Across the Face of Its Star Photographic Poster Print by Stocktrek Images, 16x16
by Art.com
Art.com is the world's largest retailer of art prints, posters, photographs, and framed artwork. With our huge selection of over 400,000 prints, you'll easily find the perfect piece for your home, office, or classroom. Our art is printed on quality paper. When you order framed artwork, the piece is built by our team of in-house professionals. Visit our Amazon store today at www.amazon.com/artdotcom to find Special Offers and search for products based on 'Artist Name' and 'Subject Categories' such as Movie, Music, Vintage, TV, Children, Travel, Kitchen, Museum Art, Animals, Floral, Motivational, and Sports. Art.com is dedicated to providing you with high quality products and service by offering you 100% satisfaction guaranteed. We ship internationally to over 80 countries. Decorate your...
|

|
Formation and Evolution of Exoplanets
by Rory Barnes (Editor)
This single, coherent review of the theory behind extrasolar planet formation and interaction systematically covers all aspects of the topic, including different formation processes, planet-planet scattering, giant planets and brown dwarfs. With a chapter on observation, careful referencing and an elaborate bibliography at the end of each chapter, this is indispensable reading for researchers, theorists and observers alike.
|
|