Astronomers say they've successfully tested a new optic system capable of revealing the existence of a distant exoplanet even if it is orbiting close to its host star.
The technology, known as a "vector Apodizing Phase Plate" or vector-APP, was installed on a telescope in Chile last month and showed the ability to provide observations with unprecedented contrast very close to a star where exoplanets are most likely to be found.
While astronomers have detected around 2,000 exoplanets to date, very few have been imaged directly.
Most have been discovered indirectly, by measuring changes in the light coming from a distant star as the disk of one of its planets passes in front of it.
Direct observation of exoplanets -- often millions of times fainter than the star they orbit -- is almost impossible because they are obscured by the glare of that parent star, astronomers explain.
In an effort to image them directly, large telescopes on Earth are being fitted with instruments known as coronographs designed to suppress a star's overwhelming surrounding halo of starlight.
The vector-APP coronograph takes advantage of the wavelike character of light to cancel out the star's light while allowing the light of the exoplanet to shine through and be observed.
The technology uses advanced liquid crystal 3D patterns to create two separate images of a star, each with a dark D-shaped region on opposite sides of the star.
Taken together, the images allow the entire area around the star to be examined for the presence of exoplanets, and combining more than one layer of liquid crystals allows observations in a wide range of wavelengths.
This includes infrared wavelengths, which provide particularly favorable contrast between star and planet, the researchers say.
The test on the Chile telescope yielded immediate results, they report.
"It is fantastic to see that after all our design work and lab testing, this new approach works perfectly at the telescope on the very first night!" says Frans Snik of the Leiden Observatory in the Netherlands, the inventor of the principle at the heart of the vector -APP.
Other researchers noted the potential of vector-APP to increase opportunities for direct discoveries of exoplanets.
"With this new coronagraph we are now looking for planets around nearby stars," says Jared Males of the University of Arizona. "We have the capacity to directly detect, or rule out, planets smaller than Jupiter."
