Here is a simple constellation generator. It creates a random constellation for your fantasy sky. Sooner or later, you will probably need some zodiac signs to explain certain events and character traits.
After a few runs, it's easy to notice that the script just connects random dots and assigns them a random name. It's up to you to imagine how that shape is supposed to represent what it claims to be.
The generated image will be scaled down to fit the page, but it will have the specified resolution when saved.