Hi there! This is Val, I made the star chart. There's a little "about" blurb you can open in a modal on the site, but I wanted to mention that this demo uses the amazing GAIA DR3 dataset from ESA. I have a Python script that renders all 1.8+ billion stars into custom images, which is what I used for the skybox. The star positions and colors all use the GAIA data (save for a few bright stars not in the set). The data is amazing, and if you have any interest in doing some fun projects with open data I recommend checking it out: https://www.cosmos.esa.int/web/gaia/dr3

Super cool! how long did it take to generate all those custom images?