We all know Edmond Halley because he’s immortalised by the comet that bears his name, but to astronomers he has a second claim to fame: he was the first to show that the stars appear to move across ...

Astronomers have long been able to measure the movement of stars in our 'line of sight' (i.e. the movement towards or away from us) by measuring the redshift, which is caused by the Doppler effect.

Proxima Centauri, at 4.2 light-years, is the closest star to Earth, excluding the Sun; other nearby stars within 15 light-years include Barnard's Star and Sirius. Barnard's Star, a red dwarf 6 ...