Definition of "spacekin"

Frau Vanderhoeven waved to me to come over. "Greetings, spacekin!" she said. "We are only just finishing our funeral pyre."

2009, Karen Subach, “A Wolf Should Roam”, in New England Review, volume 30, number 1, Middlebury College

In addition to the otherkin identify as animals, there are some who identify as mythical creatures, like dragons, fairies, or vampires; fictionkin, who identify as fictional characters, frequently from anime series or videogames; weatherkin, like Marco, who identify as weather systems; conceptkin, who identify as abstract concepts; spacekin, who identify as celestial bodies; and several other even more obscure categories (musickin, timeperiodkin—the list goes on).

2016 August 4, Callie Beusman, “'I Look at a Cloud and I See It as Me': The People Who Identify As Objects”, in Broadly

There's plantkin, spacekin—who's to say planets don't have souls?—and a whole bunch of other Otherkin, It's not just animals.

2017, Bryant A. Loney, Take Me to the Cat, page 190