The candidate planet lies some 70 times as far from HD 100546 than the distance between the Earth and the Sun. This large distance has made its identification as a forming planet somewhat controversial, as it does not fit with current theories. It is unclear, however, whether the planet may have moved to its current position from one closer to its star.
Since the discovery of the first exoplanet around a sun-like star in 1995, several hundred planetary systems have been identified, leading to a significant growth in the theory of how planets are formed. However, up until now, there has been no direct observation (and therefore, confirmation) of the process. If the VLT's observations are confirmed, then the discovery will significantly aid our understanding of the process, allowing astronomers to test current theories for the first time.
Sasha Quanz, the leader of the team that made the discovery, commented on the significance of the find, stating that “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.”
The observation itself was made using a special coronagraph on the NACO adaptive optics instrument on the VLT, which operates at near-infrared wavelengths. Though it is most likely that the observation is that of a planet forming, the results are yet to be corroborated, and further observations are scheduled to take place in order to confirm the discovery.
Other possible explanations could be that the readings are the result of interference from a background source, or that the planet in question is in fact fully formed and has been ejected from its original orbit closer to the star. That said, if the new object is confirmed as the birth of a planet, then it will become a unique and invaluable asset in the ongoing study of the formation process of new planetary systems.
Scroll down for a video fly-through of the environment around the young star HD 100546.