Rotating vs. Stationary Mass Grav Effects?

[Spinoff]

Does a mass in rotation exert a different effect gravitationally than the same mass at rest? I recall it does.

As a thought experiment can we take a dense, small mass and place it in extreme rotation so that it's effect on the local gravational field is intensified?
This thought experiment only works with some convenient assumptions:
The mass is not distorted by the rotation.
The rotation is very extreme, let's say a laser striking our experimental object tangentially and continuously.

What would happen?
Thank you

 

[tiny-tim]

Welcome to PF!

Hi Spinoff! Welcome to PF!

Does a mass in rotation exert a different effect gravitationally than the same mass at rest?

Newton says no, Einstein says yes.

(a rotating body has extra energy, and energy is mass, so the same rotating body has more mass anyway; also, a rotating mass "drags spacetime" around with it very slightly … see http://en.wikipedia.org/wiki/Frame-dragging" for some details)