When we look at a star from the surface of the earth, we are also looking through the various layers of the atmosphere. Air has several kinds of motions. The astronomers and engineers who build telescopes are very familiar with this, because some of these telescopes are designed to get around the blurring effects of these motions. The next night the air was calmer, and the image of the star looked smaller and more stable. This would continue, until the cirrus clouds that come before the next front arrived.
Most stars are very similar to our sun.
In fact the sun is a pretty normal kind of star. It's much brighter than the other stars because it is close by. To give you an idea of how far, we can compare the time that it takes for light to travel from one place to another. Even so it takes about eight minutes for light to travel from the sun to the earth. When you look at the stars at night, some are closer and some are farther.