In an astronomical first, we may have directly observed a star forming at the same time as a world that orbits it, proving a long-held theory about planet formation .

Planets are thought to form in a disc of dust and gas, also known as a protoplanetary disc , surrounding a host star. Theoretical models suggest planets should begin to take shape while the host star is still growing – but until now, we have only seen active evidence of planet formation after the star itself had formed.

Looking at a system …