How do we know that stars are suns, and that they have planets?

Question

And how do we know their sizes and distances?

In: Physics

Answer 1

Astronomers don’t just look at objects. They measure their energy outputs, their spectrographic data, their distance and movement, etc. Everything about stars lines up with observations we’ve made about our own sun.

So either those stars are very similar structures to our sun, or someone is playing a *fantastic* trick on us.