In this guide, you will find how to use the Telescope for Star Gazing at Astronomy Table in Hogwarts Legacy.
You have to do this at night by opening up your map and pressing the Wait button. It says at the bottom right of the screen to change from day to night.
After that, interact with the telescope, zoom in, and then rotate it. Line up the constellation path that you have with the Stars, so just rotate it so that it fits the combination.
