Astronomy

How do astronomers weigh a star that's trillions of miles away and way too big to fit on a bathroom scale? In most cases, they can't, although they can get a best estimate using computer models of stellar structure.

New work by astrophysicist David Kipping says that in special cases, astronomers can weigh a star directly. If the star has a planet, and that planet has a moon, and both of them cross in front of their star, then scientists can measure their sizes and orbits to learn about the star.