Know about the innovative instrument which can picture exoplanets

New Delhi: An exoplanet is a planet outside the Solar System. For centuries philosophers and scientists supposed that extrasolar planets existed, but there was no way of detecting them.The first confirmed detection of exoplanet came in 1992, with the discovery of several terrestrial-mass planets orbiting the pulsar PSR B1257ი.Now till date more than a thousand such planets have been discovered.After discovering these exoplanets, now researchers at University of California have also secured success in developing an instrument which can click the pictures of these planets.The team used a prototype instrument called the Fibered Imager for Single Telescope (FIRST) earlier this year.This instrument was made with the combination of two high-resolution telescope techniques - adaptive optics and interferometry .The astronomers mounted an improved instrument on the Subaru 8-meter telescope in Hawaii that has the potential to one day resolve exoplanets, or Earth-like planets around M-type “dwarf” stars, which are slightly smaller and cooler than the sun.The FIRST instrument on the Subaru telescope uses 18 fiber optic cables to sample spots on a larger 8-meter main mirror. The 3-meter Lick and 8-meter Subaru telescopes are already equipped with adaptive optics, which creates sharper images by removing the jiggle in stars caused by turbulence in the atmosphere.One of the key components of the system is a tiny movable mirror, a microelectromechanical systems or MEMS device, that directs starlight into the optical fibers, which channel the light without much loss to the interferometer.FIRST takes advantage of the stability provided by the adaptive optics system to inject the light from the star into the precise center of the fibers, which have a core a mere 4 micrometers in diameter.The key advantage of FIRST is that it can resolve very close objects, such as close binary stars or the disks of dust and gas that circle stars in the process of forming planets. It can even resolve the surface features on red supergiant stars, which bloat to the diameter of Earth's orbit. Other techniques are limited by the turbulent glare from the stars, which is effectively removed by the use of fibers in FIRST.In the December issue of the journal Astronomy and Astrophysics, University of California, Berkeley report that they were able to resolve in visible light the two stars in the binary star system Capella, which orbit one another at about the distance of Venus from the sun and until now have been indistinguishable from Earth with the help of FIRST.