why do the spots pulsate?

Answer 1

The pulsating spots, often seen in various celestial bodies or phenomena, can be attributed to changes in brightness or energy output. In stars, for instance, pulsations can result from internal processes such as thermal expansion and contraction, leading to varying surface temperatures and luminosities. In other contexts, like certain types of nebulae or variable stars, pulsations may be caused by gravitational forces or energy fluctuations within the object. These dynamic changes create a visual effect of pulsating light or color.