We would expect exoplanets (planets outside of our solar system) to follow the same orbital mechanism as that of the planets in our own solar system. However, the discovery of a planet has proved otherwise. Recently, astronomers have discovered a planet, three times the size of Jupiter that follows an elliptical (oval-shaped) orbit rather than a relatively circular one around its star.
In order to detect such planets, astronomers use the method of Radial Velocity. This is done by analyzing how parent stars vibrate in response to the gravitational force exerted by their planets. This is indeed a tedious process as some planets orbiting a long distance away from their stars may take decades to complete their orbit. Astronomers had been studying this planet’s star HR 5183 since 1990 and it was predicted that this planet would circle its star every 45 to 100 years. But then how were the astronomers able to detect the planet in 29 years only?
Due to the planet’s highly eccentric or oval-shaped orbit, it spends most of its time wandering away from its star. However, as it comes closer to its star, it accelerates and swiftly slingshots around its star due to gravitational force. Even though the planet has not completed its orbit yet, astronomers were able to detect the swift motion and confirmed the presence of the planet and its trajectory path.
The discovery of HR 5183 planet’s orbital path is significant as it reiterates that the mechanisms in other exoplanets are not carbon-copies of the mechanisms in our solar system. Our understanding of the new worlds in space is still developing, however, it is discoveries like these that lead to the improvement of existing methods of space exploration.