Logical Topology
Logical topology defines how the signal travels, not the physical layout.
A logical bus means that the signal will go out from the sending station in all directions to every host.
The physical topology may be a bus or a star.
In a physical star that uses a logical bus, the central device will be a hub. This may be referred to as a star-bus topology.
The first part (star) represents the physical topology and the second part (bus) represents the logical topology.