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Q & A: Why are stars dots in the sky?

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Most recent answer: 10/30/2016
Why are stars dots in the sky?
- Ancient (age 20)
athens, greece

They appear to be dots because they are so far away.    If you look with your naked eye all of the stars appear as dots. The smallest angular size a lens can resolve is proportional to the wavelength of the light divided by the diameter of the lens. The eye has a diameter of a few millimeters.   However the Hubble Space Telescope has a much larger diameter  (2.4 meters) and its angular resolution is good enough to measure the diameter of a half-dozen of the closest stars.


(published on 10/30/2016)

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