By Sykes criteria, the smallest known planet in the solar system would be Ceres, the largest and most massive object in the asteroid belt. Ceres is less than half the diameter of Pluto.

Sykes, director of the Planetary Science Institute is talking about planets across the universe in general, about Pluto and other small
planets in particular, [...]

R136-  A Cluster of Massive Stars in the Doradus Nebula

I like to go beyond just recreations, imagining what unknown worlds lie in such places.  Perhaps even advanced cultures with space vessels traveling about.

Tal Doradus -11

I enjoy visualizing what it would look like from the surface of a planet near such a captivating nebula.  To see [...]