Does mass or size effect the orbital period? thanks
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question 1) Newton's version took into account only the actual Sun and its planets, since stars were only suspected of being suns by scientists then. And then, few if any astronomers said stars had planets, or had different masses than our star.
If a star has more mass than our sun, a planet with mass of Earth at 1 AU must have a shorter period in order to be in orbit. Alternative to that would be to have a larger orbit, but a period of 1 year.
question 2) Imagine an ice skater in a spin. As the arms go in, the rotational speed increases, but the mass stays the same. To stop abruptly, the skater throws arms and legs wide. If a star shrank in physical size but was at the same distance, its angular size would shrink. AND it would rotate faster on its axis.
If a star has more mass than our sun, a planet with mass of Earth at 1 AU must have a shorter period in order to be in orbit. Alternative to that would be to have a larger orbit, but a period of 1 year.
question 2) Imagine an ice skater in a spin. As the arms go in, the rotational speed increases, but the mass stays the same. To stop abruptly, the skater throws arms and legs wide. If a star shrank in physical size but was at the same distance, its angular size would shrink. AND it would rotate faster on its axis.
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Size has no effect, unless things bump into each other.