We draw and design pointed stars so that we perceive the real stars in the sky. The reason is partly the earth’s atmosphere, partly the structure of our eyes.
From the earth’s surface, stars look like twinkling dots. This is because the air above us is never completely still. The atmosphere is filled with tiny eddies and bubbles that create differences in the density of the air.
The differences act like lenses that constantly refract starlight in new ways, making it appear as though the stars are twinkling.
Spikes occur in our eyes
At the same time, the human eye has small defects that cause light to scatter differently. Diffusion creates the pattern that our brain perceives as spikes.
The same effect occurs in the Hubble telescope’s camera, causing it, too, to show pointed stars.
