New analysis of archival data reveals the presence of shocked gas in the protoplanetary disk surrounding the young star TW Hydra. The discovery suggests the presence of a planet four times the mass of Earth and gives researchers a rare opportunity to study the early stages of planet formation. Baby planets form in disks surrounding young stars, but the details of this process remain unclear, especially since the planets are often hidden from view by being shrouded in dusty gases.

Massive gas planets like Jupiter and Saturn are thought to form by gas accumulating in their rocky cores and gradually cutting a trail of gas into the disk. What do model calculations tell us about the origin of this ejection? Using a ballistic outflow model, the authors showed that the SO outflow can be explained by a growing planet with a mass four times the mass of the Earth. By combining estimates of the mass accretion rate and the mass loss rate, the team found an overall growth rate of the planet that is consistent with theoretical predictions for a planet with four times the mass of the Earth.

With evidence of the outflow already available, Yoshida’s team will continue the search and will carry out further observations to look for evidence of the outflow in the emission of other promising molecules such as silicon monosulfide.

Overall, the study supports new evidence for the presence of a planet in the 42 AU gap in Hydra, and future observations can be expected to shed more light on this growing family of planets.