The planet Kepler-186f was named after the Kepler space telescope, which discovered it. The telescope was named after the German astronomer Johannes Kepler, who is famous for his laws of planetary motion.

Here's why the naming convention is used for exoplanets:

* Discovery Instruments: The primary method of naming exoplanets is to use the name of the instrument that discovered them. This allows for a clear and organized system for tracking and referencing these celestial objects.

* Honoring Legacy: Naming exoplanets after important figures in astronomy, like Johannes Kepler, acknowledges their contributions to the field and provides a link to the historical development of our understanding of the universe.

Therefore, Kepler-186f is named after the Kepler telescope because it was the telescope that detected and confirmed the planet's existence.