I was not really implying that stars pulsate, just that it takes your eyes a few tenths of a second to register. look at it this way: Have you ever tried to look at the international space station? If you manage to get a good seven or eight minute window during twilight you can barely see what looks like a bright star moving across the sky as the sun reflects off solar panels the size of a football field. The space station orbits at 354KM or 220 miles up. Now suppose the something the size of the enterprise was parked right 1 meter above you at high noon. Ignore inertia and what it would do to the atmosphere and assume the enterprise takes off straight for the sun instantaneously at light speed (186000 miles per second). In 1/845th of a second it will be the height of the space station in orbit. It will look just as big, and block as much of the sunlight as the space station does when it travels across the sky above you. In 1.28 seconds it would be passing the orbit of the moon. It would take something the size of a good moon, heading in a straight line between the light source (the sun) and you (the observer) to block enough light long enough to be detected.