Circular orbits in Kerr spacetime: equatorial plane embedding diagrams

An embedding diagram helps visualize the observer-dependent projected spatial geometry of the equatorial plane in the Kerr spacetime as Seen by a family of circularly rotating observers. This is described for the various geometrically defined families of such observers, motivated by the attempt to better understand how the spatial geometry contributes to the properties of particle motion as seen by those observers. A new family of observers is introduced for which the equatorial plane appears to be flat.