What is the closest star to Earth?

The Sun, which is worth stating plainly because it is easy to think of stars as the things visible at night and the Sun as a separate category. It is not: it is an entirely ordinary star, of a very common type, seen from close up. Every other star would look like this if you stood next to it.

It contains about 99.86 per cent of all the mass in the Solar System. Everything else - all eight planets, the moons, the asteroids, the comets - is rounding error in the leftovers. It converts something like four million tonnes of matter into energy every second, and has been doing so for four and a half billion years with roughly five billion to go.

It is also not yellow. The Sun emits across the whole visible spectrum with a peak in the green, and seen from space it is white; the yellow we perceive is what is left after the atmosphere has scattered the blue end away across the rest of the sky. On astronomers' classification it is a G-type dwarf - and dwarf, here, covers every ordinary star burning hydrogen in its core, including this one.