Scientists come closer to discovering habitable earths

Researchers have clicked photos of a planet outside our solar system with an Earth-based telescope using essentially the same type of imaging sensor found in digital cameras instead of an infrared detector.

Lead author Jared Males, a NASA Sagan Fellow in the UA's Department of Astronomy and Steward Observatory, said that this is an important next step in the search for exoplanets because imaging in visible light instead of infrared is what we likely have to do if we want to detect planets that might be suitable for harboring life.

Even though the image was taken at a wavelength that is just shy of being visible to the human eye, the use of a digital camera-type imaging sensor - called a charge-coupled device or CCD - opens up the possibility of imaging planets in visible light, which has not been possible previously with Earth-based telescopes.

He explained that all the other Earth-based images taken of exoplanets close to their stars are infrared images, which detect the planets' heat. This limits the technology to Gas Giants - massive, hot planets young enough to still shed heat. In contrast, older, possibly habitable planets that have cooled since their formation don't show up in infrared images as readily, and to image them, astronomers will have to rely on cameras capable of detecting visible light.

The photographed planet, called Beta Pictoris b, orbits its star at only nine times the Earth-Sun distance, making its orbit smaller than Saturn's. In the team's CCD images, Beta Pictoris b appears about 100,000 times fainter than its host star, making it the faintest object imaged so far at such high contrast and at such relative proximity to its star. The new images of this planet helped confirm that its atmosphere is at a temperature of roughly 2600 degrees Fahrenheit (1700 Kelvin).

The team estimates that Beta Pictoris b weighs in at about 12 times the mass of Jupiter.

The research has been published in The Astrophysical Journal.