Star Trails - D800E and 14-24mm

Having never taken more than 40 minute star traits from unlocked positions, I have a practical question: even with a star gazer (that presumably moves with Polaris), how do you keep the foreground from moving as well and ghosting?

Or was this two images pasted onto one another? The horizon shifts as the earth rotates and the relative position of polaris changes. How do you keep the changing horizon with the relative position of the stars in track?

It is an honest question.

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