May be I'm wrong, but it looks more likely like a EDSM-related functionality
Indeed, according to the API:
Thanks for the info cmdrs. I was unaware of this functionality on EDSM.
Also exists as cube: https://www.edsm.net/api-v1/cube-systems?x=12.34&y=5.6&z=7.89&size=20
Might be more performant because lees computation needed