Now you are ready to start Attuning yourself with a Star Sign. This will allow you to specify the Crystals or powers that you are able to attain. Keep your telescope close to the Celestial Altar. Not only will you need to make an Attunement Altar but you will also need to build another altar for this to sit on. This can be found in your Tome.
You will know the platform is right when you see lots of little sparkles on the ground around the Attunement Altar.
You will also need a few Spectral Relays and you will need to pick a constellation to attune yourself to (these can be found by sneak-right-clicking your Tome).
Take a Constellation Paper and put it in your off-hand. While in the Attunement Altar you will see little blue swirls on the ground that match the Constellation (you can only see this at night).
Put down Spectral Relays where the swirls appear. Once successful, the lines will connect and look like the Constellation. You can put more Relays down for other Constellations but remove at least ONE Relay from the previous Constellation (only one complete Constellation can be active at once). This will save you time in the future because you will just need to put one Relay down for a Constellation rather then all of them.
For this to work you will have needed to discover the Constellation in the sky and it must also be in the sky on that night. This process could take a few days and relies on a little luck sometimes. If your chosen Constellation is not in the sky then this process will not work. You can always change what Constellation you want to attune to by changing the Relays.
Once your Constellation is in the sky, step into the Attunement Altar and wait. Once the process has completed, you will have unlocked “perks”.