Celestarian is a non-binary xenogender in the celestial gender system. It is a combination of juparian, lunettian, and mercurian. A celestarian person may feel all of three at once or they may be fluid between them. They may feel different amounts of each at different times.
The term and flag were created by the Tumblr user Juparian on December 31, 2017. An alternate version of the flag was designed by System-Lgbt in October of 2018. The colors are based off the colors stars twinkle at night.