Black Hole Sensei (Now referred to as Black Hole Chan) refers to the Moe Anthropomorphization of a black hole. While the character saw some spread alongside characters like Earth-Chan in late 2017 and early 2018, the publication of the first image of a black hole caused many more artistic renditions of the character to appear online.
The earliest known picture of “Black Hole-chan” appeared on Pixiv on December 4th, 2015. It was drawn by user sawasawa.
The character saw more spread alongside the rise of Earth-chan in late 2017 and early 2018. One of the most prolific artists of Black Hole-chan was BSA Apricot, who posted numerous popular pieces that winter.