Science Current Events | Science News |

Optical vortex could look directly at extrasolar planets

December 01, 2005

A new optical device might allow astronomers to view extrasolar planets directly without the annoying glare of the parent star. It would do this by "nulling" out the light of the parent star by exploiting its wave nature, leaving the reflected light from the nearby planet to be observed in space-based detectors. The device, called an optical vortex coronagraph, is described in the December 15, 2005 issue of Optics Letters.

About ten years ago the presence of planets around stars other than our sun was first deduced by the very tiny wobble in the star's spectrum of light imposed by the mutual tug between the star and its satellite. Since then more than 100 extrasolar planets have been detected in this way. Also, in a few cases the slight diminution in the star's radiation caused by the transit of the planet across in front of the star has been observed.

Many astronomers would, however, like to view the planet directly-a difficult thing to do. Seeing the planet next to its bright star has been compared to trying to discern, from a hundred meters away, the light of a match held up next to the glare of an automobile's headlight. The approach taken by Grover Swartzlander and his colleagues at the University of Arizona is to eliminate the star's light by sending it through a special helical-shaped mask, a sort of lens whose geometry resembles that of a spiral staircase turned on its side.

The process works in the following way: light passing through the thicker and central part of the mask is slowed down. Because of the graduated shape of the glass, an "optical vortex" is created: the light coming along the axis of the mask is, in effect, spun out of the image. It is nulled, as if an opaque mask had been place across the image of the star, but leaving the light from the nearby planet unaffected.

The idea of an optical vortex has been around for many years, but it has never been applied to astronomy before. In lab trials of the optical vortex mask, light from mock stars has been reduced by factors of 100 to 1000, while light from a nearby "planet" was unaffected (see test figures at Attaching their device to a telescope on Mt. Lemon outside Tucson, Arizona, the researchers took pictures of Saturn and its nearby rings to demonstrate the ease of integrating the mask into a telescopic imaging system.

This is, according to Swartzlander (, 520-626-3723), a more practical technique than merely attempting to cover over the star's image, as is done in coronagraphs, devices for observing our sun's corona by masking out the disk of the sun. It could fully come into its own on a project like the Terrestrial Planet Finder, or TPF, a proposed orbiting telescope to be developed over the coming decade and designed to image exoplanets.

American Institute of Physics

Related Extrasolar Planets Current Events and Extrasolar Planets News Articles

Mars' moon Phobos is slowly falling apart
The long, shallow grooves lining the surface of Phobos are likely early signs of the structural failure that will ultimately destroy this moon of Mars.

Oxygen is not definitive evidence of life on habitable extrasolar planets
The Earth's atmosphere contains oxygen because plants continuously produce it through photosynthesis. This abundant supply of oxygen allows life forms like animals to flourish.

Astronomers discover powerful aurora beyond solar system
Astronomers have discovered the first aurora ever seen in an object beyond our Solar System. The aurora -- similar to the famous "Northern Lights" on Earth -- is 10,000 times more powerful than any previously seen.

Is salt the key to unlocking the interiors of Neptune and Uranus?
The interiors of several of our Solar System's planets and moons are icy, and ice has been found on distant extrasolar planets, as well.

Astronomers create array of Earth-like planet models
To sort out the biological intricacies of Earth-like planets, astronomers have developed computer models that examine how ultraviolet radiation from other planets' nearby suns may affect those worlds, according to new research published June 10 in Astrophysical Journal.

New exoplanet too big for its star
The Australian discovery of a strange exoplanet orbiting a small cool star 500 light years away is challenging ideas about how planets form.

Robotically discovering Earth's nearest neighbors
A team of astronomers using ground-based telescopes in Hawaii, California, and Arizona recently discovered a planetary system orbiting a nearby star that is only 54 light-years away.

Tau Ceti: The next Earth? Probably not
As the search continues for Earth-size planets orbiting at just the right distance from their star, a region termed the habitable zone, the number of potentially life-supporting planets grows.

Colorful life-form catalog will help discern if we're alone
While looking for life on planets beyond our own solar system, a group of international scientists has created a colorful catalog containing reflection signatures of Earth life forms that might be found on planet surfaces throughout the cosmic hinterlands.

ALMA finds double star with weird and wild planet-forming discs
From movies to television, obesity is still considered "fair game" for jokes and ridicule. A new study from researchers at Bowling Green State University took a closer look at weight-related humor to see if anti-fat attitudes played into a person's appreciation or distaste for fat humor in the media.
More Extrasolar Planets Current Events and Extrasolar Planets News Articles

Extrasolar Planets and Astrobiology

Extrasolar Planets and Astrobiology
by Caleb Scharf (Author)

Winner of the 2011 Chambliss Prize for Astronomical Writing from The American Astronomical Society!

This book offers an advanced introduction to the increasingly robust fields of extrasolar planets and astrobiology. No other text currently available applies this level of mathematics and physics, while also providing an extensive grounding in key issues of chemistry, biology, and geophysics. With extensive references to the literature and chapter-ending exercises, this book can be used as the core text for teaching undergraduate or introductory graduate level courses. The text will also provide astrobiologists with an indispensable "User's Manual" when quick reference to key mathematical and physical techniques is needed. A continually updated online component, fully cross...

The New Worlds: Extrasolar Planets (Springer Praxis Books)

The New Worlds: Extrasolar Planets (Springer Praxis Books)
by Fabienne Casoli (Author), Therese Encrenaz (Author)

Offering an engaging and complete story of the hunt for new worlds, this volume fully details the detection and exploration of extrasolar planets. It examines the very wide range of extrasolar planets that have been discovered during the past ten years and looks at what can be learned about such planets by studying the bodies in our own solar system. It also discusses the formation of planetary systems, the way in which such systems may evolve and the final systems of planets that result. In addition, the authors demonstrate how life might evolve on an extrasolar planet and how such life might be detected.

Extrasolar Planets (Worlds Beyond)

Extrasolar Planets (Worlds Beyond)
by Ron Miller (Author)

Color photographs enhance the explanation and description of our solar system for juveniles.

Strange Worlds: Extrasolar Planets and Their Stars

Strange Worlds: Extrasolar Planets and Their Stars
by Digital Green World Publishing

Throughout centuries, humans have wondered about the possibility of the existence of other planetary systems in the Universe. By the end of the 20th century, scientists have designed special astronomical methods and tools to detect the presence of planetary systems around other stars. The first discoveries of extrasolar planets-planets orbiting other stars-revealed planets that are very different from the planets of the Solar System. Intended for the general audience, this book reviews the story of the search, discovery and study of extrasolar planets and their parent stars.

Planets: Ours and Others:From Earth to Exoplanets

Planets: Ours and Others:From Earth to Exoplanets

What is a planet? The answer may seem obvious; still, the definition of a planet has continuously evolved over the centuries, and their number has changed following successive discoveries. In 2006, the decision endorsed by the International Astronomical Union to remove Pluto from the list of planets has well illustrated the difficulty associated with their definition. The recent discovery of hundreds of exoplanets around nearby stars of our Galaxy opens a new and spectacular dimension to astrophysics. We presently know very little about the physical nature of exoplanets. In contrast, our knowledge on solar system planets has made huge progress over the past decades, thanks, especially, to space planetary exploration. The purpose of this book is first to characterize what planets are, in...

The Planets

The Planets
by Dava Sobel (Author)

With her bestsellers Longitude and Galileo's Daughter, Dava Sobel introduced readers to her rare gift for weaving complex scientific concepts into a compelling narrative. Now Sobel brings her full talents to bear on what is perhaps her most ambitious topic to date-the planets of our solar system. Sobel explores the origins and oddities of the planets through the lens of popular culture, from astrology, mythology, and science fiction to art, music, poetry, biography, and history. Written in her characteristically graceful prose, The Planets is a stunningly original celebration of our solar system and offers a distinctive view of our place in the universe.

* A New York Times extended bestseller
* A Featured Alternate of the Book-of-the-Month Club, History Book Club, Scientific...

Extrasolar Planets: Formation, Detection and Dynamics

Extrasolar Planets: Formation, Detection and Dynamics
by Rudolf Dvorak (Editor)

This latest, up-to-date resource for research on extrasolar planets covers formation, dynamics, atmospheres and detection. After a look at the formation of giant planets, the book goes on to discuss the formation and dynamics of planets in resonances, planets in double stars, atmospheres and habitable zones, detection via spectra and transits, and the history and prospects of ESPs as well as satellite projects.
Edited by a renowned expert in solar system dynamics with chapters written by the leading experts in the method described -- from the US and Europe -- this is an ideal textbook for graduates, students in astronomy, and astronomers.

Extrasolar Planets: Saas Fee Advanced Course 31

Extrasolar Planets: Saas Fee Advanced Course 31
by Patrick Cassen (Author), Tristan Guillot (Author), A. Quirrenbach (Author), Didier Queloz (Editor), Stephane Udry (Editor), Michel Mayor (Editor), Willy Benz (Editor)

Research on extrasolar planets is one of the most exciting fields of activity in astrophysics. In a decade only, a huge step forward has been made from the early speculations on the existence of planets orbiting "other stars" to the first discoveries and to the characterization of extrasolar planets. This breakthrough is the result of a growing interest of a large community of researchers as well as the development of a wide range of new observational techniques and facilities. Based on their lectures given at the 31st Saas-Fee Advanced Course, Andreas Quirrenbach, Tristan Guillot and Pat Cassen have written up up-to-date comprehensive lecture notes on the "Detection and Characterization of Extrasolar Planets", "Physics of Substellar Objects Interiors, Atmospheres, Evolution" and...

Scholastic Discover More Reader Level 1: Planets (Scholastic Discover More Readers)

Scholastic Discover More Reader Level 1: Planets (Scholastic Discover More Readers)
by Gail Tuchman (Author)

A level 1 reader in the Scholastic Discover More Reader series.

PLANETS guides beginning readers on a journey of exploration through the solar system, showing how planets were formed, their attraction to stars, moons, and satellites, and how we humans explore our space neighborhood--the Milky Way galaxy--and beyond. A companion digital book poses evidence-based questions through fun Q&A, matching games, writing activities, and vocabulary "slams" that test the reader's comprehension.

Planets: The Solar System & Extra-Solar Planets

Planets: The Solar System & Extra-Solar Planets
by Astrid Z Ohlmeier (Author), N Nasa (Photographer), Damian Peach (Photographer)

The planets in the solar system are well known to us.The radius, atmosphere, temperature and composition of each planet are clarified, including the number of moons. This will provide a better understanding regarding the nature of planets outside the solar system or extra-solar planets. The Kepler Space Telescope holds the data of over 3500 possible planets and 238 have been confirmed. The book contains images of the solar system by NASA and a Planetary Photographer, including the Kepler Star Field with a variety of images. This new edition is for everyone, for professional scientists and for those who enjoy to learn more.

© 2015