This brightness acts as a cosmic clock that researchers can use to track time across the universe. Observing quasars over time allowed a team of astronomers to see how the universe seemed to speed ...

Pulsars can spin hundreds of times each second, and the stable precision of the pulses makes them as reliable as cosmic clocks. When gravitational waves pass between Earth and a pulsar ...

Each image corresponds to a different moment in the explosion, a true cosmic clock for astronomers. The supernova H0pe, of type Ia, is a valuable tool for measuring the Hubble constant.