Astronomers studying the disc of gas and dust surrounding the young star HD 100546, which at 335 light-years is relatively near to Earth, believe they are witnessing the birth of a gas giant similar to Jupiter, although up to three times larger.
If their discovery is confirmed, it would allow huge leaps in our understanding of how planets take shape by allowing scientists to compare their theories against direct observations from the new planet.
Dr Sascha Quanz of ETH Zurich, a Swiss university, explained: "So far, planet formation has mostly been a topic tackled by computer simulations.
“If our discovery is indeed a forming planet, then for the first time scientists will be able to study the planet formation process and the interaction of a forming planet and its natal environment empirically at a very early stage.