Earths Rotation Visualization in a Timelapse of Milky-way Galactic Core

In a regular Timelapse earth is stable and sky moves and since we are on earth we feel that we are stable and everything around us is rotation like sun raising from East etc but in reality stars in sky are stable and we rotate. For us to visualize this a Timelapse is need but keeping stars as stable . This can be achieved using a device called Sky Tracker or Star tracker. 

About Sky Trackers

A star tracker is a motorised, equatorial mount that fits on top of a tripod and allows a camera to follow the stars (or a planet, a comet, or anything else) as they are carried across the sky by the rotation of Earth. How they work is by rotating at the same speed as the Earth, just in the opposite direction. 

For star trackers to work as intended, they do need to be aligned with the Earth’s axis. This is commonly referred to as polar alignment. Polar alignment is the process of accurately aligning the polar axis of your mount with the north (or south) celestial pole. The polar axis does not move when you move the Camera.  Simply put, you need to make sure that your telescope mount is rotating on the exact same angle the sky turns on

Once your sky tracker is set mount the camera and compose a shot of your liking . If you are shooting at 20 secs exposure make sure you have 60 secs gap before shooting another picture . Using a external trigger or inbuilt interval function in camera shoot for close to 4hrs . This will give you 200+ shots that would have been captured with milky way galactic core being stable and earth changing . 

Now edit these individual images and make a video out of them and you will get to visual Earth rotation ​