Not everyone is convinced with this theory, with some experts suggesting that there could be a gamut of reasons for objects like 2015 BP519 to be nudged into puzzling orbits, given how little we know about the early Solar System.
An worldwide team of astronomers using data from experiment Dark Energy Survey, has discovered a new TRANS-Neptunian object 2015 BP519. He added that it is only the existence of the BP519 that strengthens the planet nine presence. Actually, this is the most extreme Trans-Neptunian Object ever found. Simulations in which the solar system only had eight planets didn't give 2015 BP519 the same orbit that it has now. The movement of 2015 BP519 fits perfectly into this model, so while it isn't complete proof of planet nine, it adds a crucial piece of evidence for a planet-sized entity, whose gravity is shepherding its neighbours in the outer Solar System. The new discovery was made by astronomer David Gerdes who says that the presence of an object like this bolsters the case for Planet Nine.
Planet Nine was first discussed in 2016, when a group of icy objects at the far edges of the solar system were found to be tilting in their orbits.
Trans-Neptunian Object study suggests existence of ninth planet
Scientists estimate that the object has an extremely elongated orbit, small and large radii which reach 35 and 862, respectively, astronomical units (an astronomical unit equals the average radius of Earth's orbit). In the year 2017, a statement from NASA had come up which said that there could be a ninth planet with a size probably bigger than the Earth having a mass ten times heavier than our planet. The anomaly is that unlike all the other planets orbiting the sun, the unusual object orbits at a 54° angle. Astrophysicist Konstantin Batygin from Caltech said that there are now five different lines of observational evidence that point to the existence of a ninth planet.
After that another paper was published saying that the orbit of Planet Nine may be pulling the planets 6° away from the equator of the Sun.
There's been a number of studies that have offered evidence for the existence of Planet Nine, but this new research provides one of the most persuasive arguments yet.