I think I answered a few questions like this before. The bottom line is that if the Sun vanished without any violence, there will not be any instantaneous effects. It will take 8.5 minutes for its loss to affect Earth's orbit. Then, there should be a sudden drop in the Earth's ocean tides by about a factor of 30 percent because the Sun's tidal effect on the Earth is about 1/2 that of the Moon's ( Sun + 2 Moon = Full tide). Then, of course, the daylight side of the Earth will instantly switch to night time. If the Moon happened to be visible before the event, after 8.5 minutes it will switch from being illuminated to being 'New'. After that, there will be a gradual changes as the Earth leaves its previous orbital path, moving in a straight line at 30 kilometers/sec tangent to its location 8.5 minutes after the event. But by then no one will really care!