An experimental imaging device now being built may soon deliver the first pictures of planets outside our solar system.
That’s what Dr. Ben Oppenheimer, leader of the Lyot Project, announced to U of T’s astronomy faculty in a talk last Friday. Oppenheimer works at the American Museum of Natural History in New York City.
Using indirect methods, astronomers have already identified over one hundred planets orbiting other stars. But these indirect techniques don’t tell us much about the planets themselves.
Actually getting pictures of one could reveal everything from a planet’s mass to what kind of atmosphere it has.
That would be “a very important technical and scientific landmark,” according to U of T astronomy professor Ray Carlberg, who attended the talk.
But getting pictures of one of these “extra-solar planets,” as they are called, has so far been impossible. That’s because the planets get washed out in the glare of their parent stars.
“You have this whopping bright star in the way and you’re trying to see a very, very faint object right next to it,” Oppenheimer said.
Even a Jupiter-sized planet would be one billion times fainter than its parent star.
The Lyot project combines two tricks to overcome this problem. The first is to correct for atmospheric distortion using a mirror that changes its shape up to a thousand times each second. The mirror is thin enough to be flexible and has hundreds of tiny motors attached to its back to make adjustments.
The second trick is to put something opaque in the telescope’s light path to block out most of the light from the center of the image, where the star is.
This makes any surrounding planets much easier to see.
The Lyot Project gets its name from Bernard Lyot, who invented the light-blocking technique in the 1930’s in order to observe the faint outer atmosphere of the Sun.
The Lyot device will be attached to the Advanced Electro-Optical System (AEOS) telescope in Hawaii, which was built by the U.S. Defense Department for satellite tracking.
The team will start observing in October, and they hope to bag the first pictures of planets outside the solar system a year or two after that. But there is competition from a University of Montreal team, which is taking a similar approach.
“There is no question that one of these groups—or yet other competitors—is likely to succeed in the near future,” Carlberg said.
“Someone should succeed in the next two years.”
The subject of extra-solar planets “is probably creating the most excitement in astronomy as a future area,” he added.
