Exoplanets

In news– Recently, Indian Astronomers have found a new method to understand the atmosphere of exoplanets.

Key updates–

In the recent past, astronomers have discovered that many other stars have planets going around them, like our Solar System.
Till now, around 5000 such exoplanets have been detected.
Recently, Aritra Chakrabarty, a postdoctoral researcher at Indian Institute of Astrophysics (IIA), Bangalore, developed a detailed three-dimensional numerical method and simulated the polarization of exoplanets.
Just like the Solar-planets, exoplanets are slightly oblate due to their rapid spin rotation.
Further, depending on its position around the star, only a part of the planetary disk gets illuminated by the starlight.
This asymmetry of the light-emitting region gives rise to non-zero polarization.
The polarization at different wavelengths is sufficiently high and hence can be detected even by a simple polarimeter if the starlight is blocked.
It helps study the atmosphere of the exoplanets along with its chemical composition.
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.

What are exoplanets?

Exoplanets are planets that lie beyond our solar system.
Most orbit other stars, but free-floating exoplanets, called rogue planets, orbit the galactic center and are untethered to any star.
The first possible evidence of an exoplanet was noted in 1917, but was not recognized as such.
The first confirmation of detection occurred in 1992.
This was followed by the confirmation of a different planet, originally detected in 1988.

Exoplanets are very hard to see directly with telescopes.
They are hidden by the bright glare of the stars they orbit.
So, astronomers use other ways to detect and study these distant planets.
They search for exoplanets by looking at the effects these planets have on the stars they orbit.