Spring Break
Groups take first photos of extrasolar planets
Issue date: 11/20/08
Astronomers have taken the first direct images of planets outside of our solar system. The visible images were taken of planets orbiting the star Fomalhaut, located 25 light years away from Earth in the constellation Piscis Austrinus.
In a separate study, an exoplanetary system comprised of three planets circling a star 130 light-years away in the constellation Pegasus, was directly imaged. These findings were published online in the journal Science.
None of the four planets are remotely habitable, nor do they resemble Earth. In fact, the four gas giants are much more similar to Jupiter. However, scientists have not ruled out the possibility that either planetary system contains Earth-like worlds.
The search for extrasolar planets has, until now, employed two techniques. Many astronomers have focused on detecting the "wobble" that planets induce on their parent star. Stars and planets, like all objects with mass, exert a gravitational force on other objects.
While the gravitational force exerted by stars keeps planets in their orbit, the gravitational force exerted by planets causes their parent stars to wobble in place. This movement can be observed by examining the light coming from the stars.
Scientists could also wait for the planet to transit or pass in front of its star. A planetary transit would result in a temporary, detectable decrease in the star's brightness. Most planets discovered using these techniques have been very large, many larger than Jupiter.
While these techniques have led scientists to discover over 300 extrasolar planets, scientists have struggled to directly image these planets. These recent images are very significant. For the first time, a planet, rather than the effects of a planet, have been observed. Images would be valuable in determining the composition and atmosphere of extrasolar planets. The same technology could be applied in the search of new Earth-like planets.
However, there are two major problems that need to be overcome: Earth-like planets will most likely be orders of magnitude fainter than gas giants like Jupiter. Second, terrestrial planets will be located much closer to their parent star, making them more difficult to image.
In a separate study, an exoplanetary system comprised of three planets circling a star 130 light-years away in the constellation Pegasus, was directly imaged. These findings were published online in the journal Science.
None of the four planets are remotely habitable, nor do they resemble Earth. In fact, the four gas giants are much more similar to Jupiter. However, scientists have not ruled out the possibility that either planetary system contains Earth-like worlds.
The search for extrasolar planets has, until now, employed two techniques. Many astronomers have focused on detecting the "wobble" that planets induce on their parent star. Stars and planets, like all objects with mass, exert a gravitational force on other objects.
While the gravitational force exerted by stars keeps planets in their orbit, the gravitational force exerted by planets causes their parent stars to wobble in place. This movement can be observed by examining the light coming from the stars.
Scientists could also wait for the planet to transit or pass in front of its star. A planetary transit would result in a temporary, detectable decrease in the star's brightness. Most planets discovered using these techniques have been very large, many larger than Jupiter.
While these techniques have led scientists to discover over 300 extrasolar planets, scientists have struggled to directly image these planets. These recent images are very significant. For the first time, a planet, rather than the effects of a planet, have been observed. Images would be valuable in determining the composition and atmosphere of extrasolar planets. The same technology could be applied in the search of new Earth-like planets.
However, there are two major problems that need to be overcome: Earth-like planets will most likely be orders of magnitude fainter than gas giants like Jupiter. Second, terrestrial planets will be located much closer to their parent star, making them more difficult to image.
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