Tuesday, February 23, 2016
New imaging technique can find Earth-like planets near their stars
Astrophysicists have long been on the lookout for planets where life may exist—very generally, those in a sweet spot of being close enough to a star so the planets are warm, but not too warm to support life. The only problem is, often these planets are difficult or impossible to see through a traditional telescope because the brightness of their star drowns out the tiny bit of light reflected by the planet—kind of like trying to see a firefly next to a lighthouse but much, much harder.
"Current instrument technology is very complex and expensive and still a ways off from achieving direct images of Earth-like planets," added Florida Institute of Technology astrophysicist Daniel Batcheldor in a statement.
New solution to an old problem
But now there is new hope, according to a new paper in Publications of the Astronomical Society of the Pacific, as researchers led by Batcheldor have shown that something known as a charge injection device, or CID, might be a viable (and significantly less expensive) solution to this problem.
A CID is used as a type of camera: It takes in and captures light, but it can capture light from objects that are tens of millions of time dimmer than other objects in the same picture—like a planet next to a bright star, for example.
The camera can do this because each of the camera's pixels work independently from each other. So, when looking at a star, the pixels capturing the star get addressed and capture its light very quickly, while pixels representing something fainter near the star take more time to gather the object's dimmer light.
"The CID is able to look at a very bright source next to a very faint source and not experience much of the image degradation you would normally experience with a typical camera," said Batcheldor.
In the study, Batcheldor and several graduate students used Florida Tech's 0.8-meter (2.6-foot) Ortega telescope were able to pick out objects in the glare of the brightest star in the night sky, Sirius. But not just any objects: Ones that were 70 million times dimmer, meaning CID is more than 1000 times better than a regular astronomical camera.
"If this technology can be added to future space missions, it may help us make some profound discoveries regarding our place in the universe," said Batcheldor.