My headcanon is that the neologism was coined by Vicky Karayiannis, widow of Chris Cornell.

https://en.wikipedia.org/wiki/Chris_Cornell#Personal_life

The modern Greek terms for "black hole" are:

μαύρη τρύπα or μελανή οπή

https://el.wikipedia.org/wiki/%CE%9C%CE%B1%CF%8D%CF%81%CE%B7...

helio- cannot mean "star" in a generic way but invariably refers to our own Sun. If referring to some other star, then we use aster-.