Context: Indian Astronomers have found a new method to understand the atmosphere of extra solar planets.
They have shown that planets going around stars other than the Sun can be studied by observing the polarisation of light and studying polarisation signatures.
These polarisation signatures or variations in scattering intensity of light can be observed with existing instruments and expanding the study of planets beyond the solar system using existing instruments.
The thermal radiation of hot young planets and the reflected light of planets orbiting other stars, known as extra-solar planets or exoplanets would also be polarized and the measure of the polarization might unveil the chemical composition and other properties of the exoplanetary atmosphere.
Subsequent confirmation of the prediction by the detection of polarization of many Brown Dwarfs, a kind of failed stars that have an atmosphere very similar to that of Jupiter, motivated researchers all over the world to build highly sensitive polarimeters and use polarimetric methods to probe exoplanetary environment.
Unlike the traditional and popular methods such as Transit Photometry and Radial Velocity methods that can detect planets that are viewed almost edge-on only, this polarimetric method can detect and probe exoplanets orbiting with a broad range of orbital inclination angles.
Thus, polarimetric techniques in the near future will open up a new window for the study of the exoplanets and enable us to overcome many of the limitations of the traditional techniques.
