Overview
StarCar is a permanently free linear star systems cartography tool. It enables GMs running sci-fi campaigns to visualize and share star maps with their players easily. It allows a lot of different customizations for orbital bodies, like planets, secondary stars, Ringworlds, Dyson Spheres, and more.
GMs can add notes to individual orbital bodies, stars, and moons. The notes can be totally customizable, or use either
Traveller 
https://groupfinder.eu/library/traveller-2e-2016 or Stars Without Number rules. If they want, the GM can even export a stylized PDF report that details all the notes in an easy-to-follow format.
And if the GM just needs something right away? StarCar will roll the dice and generate a totally randomized system: random stars, planets, and even randomized plot hooks.
Once the GM is finished, they can export it in a number of different formats: PNG, WebP, or JPG, or with settings like Printer Friendly or Transparent Background. Anything exported is licensed under Creative Commons 4.0, which means the person who makes it owns it. They can even use it in any products they sell, with attribution.
Links
starcar.grumpycorngames.com https://starcar.grumpycorngames.com/ - Starcar website