One of the most advanced camera in the world is helping researchers detect hidden planets located around nearby stars.
An international team that included physicists from the University of California Santa Barbara has developed the DARK-speckle Near-infrared Energy-resolved Superconducting Spectrophotometer (DARKNESS), the first 10,000-pixel integral field spectrograph that can overcome the limitations of traditional semiconductor detectors.
The camera employs Microwave Kinetic Inductance Detectors that can work with a large telescope and an adaptive optics system to enable direct imaging of plants around nearby stars.
“Taking a picture of an exoplanet is extremely challenging because the star is much brighter than the planet, and the planet is very close to the star,” UC Santa Barbara physicist Benjamin Mazin said in a statement.
DARKNESS can take the equivalent of thousands of frames per second without any read noise or dark current, which are among the primary sources of error in other instruments. The device can also determine the wavelength and arrival time of every photon, which helps scientists distinguish between planets from scattered or refracted light called speckles.
“This technology will lower the contrast floor so that we can detect fainter planets,” Mazin said. “We hope to approach the photon noise limit, which will give us contrast ratios close to 10-8, allowing us to see planets 100 million times fainter than the star. At those contrast levels, we can see some planets in reflected light, which opens up a whole new domain of planets to explore. The really exciting thing is that this is a technology pathfinder for the next generation of telescopes.”
DARKNESS acts as both a science camera and a focal-plane wave-front sensor, quickly measuring the light and then sending a signal back to a rubber mirror that can form into a new shape 2,000 times a second. This cleans up the atmospheric distortion that causes stars to twinkle by suppressing the starlight and enabling higher contrast ratios between the star and the planet.
The device was designed for the 200-inch Hale telescope at the Palomar Observatory near San Diego and has been on four runs in the last year and a half. The team will return in May to take more data on certain planets. The researchers also plan to demonstrate progress in improving the contrast ratio.
“Our hope is that one day we will be able to build an instrument for the Thirty Meter Telescope planned for Mauna Kea on the island of Hawaii or La Palma,” Mazin said. “With that, we’ll be able to take pictures of planets in the habitable zones of nearby low mass stars and look for life in their atmospheres. That’s the long-term goal and this is an important step toward that.”
The study was published in Publications of the Astronomical Society of the Pacific.