An exoplanet is a planet that orbits a star not within our solar system.
Formation of an exoplanet
Before an exoplanet is formed, a star must be formed. The very beginning of the formation of a star begins with a gas and dust cloud, known as a molecular cloud which is a kind of nebula. The molecular cloud is mostly made up of hydrogen and helium gas. As the elements begin to clump together, the gravity of the clumps grow. This causes the mass to form a spinning cloud disk, known as a protoplanetary disk with a protostar in the center. As the protostar’s temperature increased due to the increased gravity and therefore kinetic energy, the disk continued to spin faster and get flatter. Once the temperature reached 10 million degrees Kelvin, the hydrogen and helium begin to undergo nuclear fission. This is where atoms will collide and fuse together to form larger and heavier elements. In the outer parts of the disk, the materials or dust begin to clump together as well, forming large masses called planetesimals, which would eventually become planets. The planets formed closer to the center of the disk,
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In almost all cases, they are too far away to be seen by a telescope. Two notable methods used to detect exoplanets are the Doppler Method and Transit Method.
Doppler Shift Method
The doppler shift method works by analysing the doppler effect that occurs when a planet orbits its star. The doppler effect is when a small mass, such as a planet orbits around a larger mass, such as its star, which will cause a shift or wobble as both masses have a gravitational pull towards each other, thus they will both orbit a common central point. It is most effective when looking at larger planets that are orbiting nearer to its star. This is because the shift or wobble will be more evident and therefore a more certain conclusion can be made about whether or not there is an exoplanet orbiting the