Suppose our Sun is hit by a star of equal mass, traveling in the opposite direction. The two stars fuse mechanically and remain in rest (in the frame of their center of mass).
1) Will an ultra-sensitive seismometer, located on Earth, detect such gravitational disturbance?
2) I think that the speed of the disturbance would be practically c, in the frame of the center of mass. Yes or NO ?
Ludwik Kowalski, Professor Emeritus
Montclair State University, NJ