A legend is a traditional story that explains something in real life. Sometimes they are accepted as true, but sometimes they are fantastical and just plain fun. There are many legends that surround the North Star explaining its creation as well as why it is stationary.
Take some time to research some of the legends of the North Star. After you have had a chance to read several of them, create your own fantastical story of the North Star. It can be how it came to be or explain why it is stationary.