To discover any exoplanet is indeed a difficult job and it is amazing that we’ve found out some of the exoplanets of all based on the given challenges. Astronomers are so clever that they have found out more than 4300 exoplanets ranging from mercury size to planets larger than the Jupiter and most of the exoplanets have one thing in common that they are close to their home stars. It is not that every exoplanet is close to their orbit stars but their observation is partial towards the close exoplanets. The most general way of exoplanets to get discovered is known as transit method. In this method when a planet is passing from a star making the star dimming slightly. This method looks very simple when we think of it but when it comes to practically apply it is very difficult. The brightness of the star varies differently in terms of flares and starspots and to confirm an exoplanet based on this you need to observe every recurring pattern of the way a star dims. You can confirm a planet quickly if it orbits around that star every few days or months but if it takes a time of couple of years then you need more observations to be sure.
Even the research was partial we have learned so many things about the universe like hot jupiters which orbit around their stars in a matter of days and also the carbon worlds that are very different from the earth. Now we also have idea about that our solar system with its inner planets are made up of rocks and the outer planets that are made up of gases which are not typical for most of the star systems. We are only less aware about the planets that orbit their stars over years or longer but that too have started changing according to the recent paper.
The Kepler mission was used to find most of the exoplanets that have orbital periods longer than 100 days which are very difficult to confirm. The transit method only tells us about the size of the planet related to its star and the Kepler mission doesn’t allow us to calculate the mass of the planet which is very difficult for Jupiter sized planets. The main goal of the Giant Outer Transiting Exoplanet Mass survey or the GOT’EM survey is to determine the mass of the exoplanets which is very essential.They also used radial-velocity method to determine the exoplanets, that orbits to its stars gravitationally causing the star to slightly shake. And when that star was shaken the light of the star is changes to blue and red due to Doppler effect. This method is particularly used to calculate the mass of large planets as the amount of wobble depends on it masses.
Kepler-1514b an exoplanet which was discovered in 2016 orbit its stars after every 218 days. The research team focused on that, its diameter is about 10% of the Jupiter and also determined the mass of the exoplanet by using Keck Observatory telescopes in Hawaii which was about 5.3 Jupiters. The Nancy Grace Roman Space Telescope which was scheduled to be launch in 2025 which will try to find large exoplanets directly using the GOT’EM survey.