Indian scientists find new way to measure distances in deep space

Indian astronomers, including from IIT-Kanpur, have developed a new way to measure distances in the universe using the pulsating cores of dead stars, by studying how their radio emissions are distorted as they travel through space. The technique combines a pair of subtle effects that occur when pulsar signals pass through clouds of ionised gas in the Milky Way.

The dense and rapidly spinning remnant cores of dead stars are called pulsars. They emit beams of radio waves that sweep across the earth like light from a lighthouse sweeps across ships at sea. Pulsars have an extraordinarily fixed spinning rate, so the pulses arrive very regularly. So astronomers have used them as cosmic clocks.