These sightings of Nibiru are most likely supernatural demonic UFO phenomena.  This has been happening throughout human history. As the restraining hand of GOD the Holy Spirit is lifted we will see more of this.
 
During the daytime there is another phenomena called ""Sun Dogs"".  In effect, atmospheric refraction makes the sun appear in two or three places in the shy.
 
I must point out that there are a huge number of talented amateur astronomers looking for Nibiru/ planet X   and not one has yet seen it.
 
Lewis  Brackett