A team of international astronomers has discovered a gas giant orbiting a distant star with characteristics remarkably similar to those of our own Jovian planet, Jupiter. The significance of the discovery is that the gas giant was found to orbit roughly the same distance from its host star HIP 11915, as Jupiter does from the Sun. This positioning may have profound implications for creating conditions favorable to the development of a habitable Earth-like planet in HIP 11915's inner solar system.
Current exoplanet hunting techniques are only really useful for discovering very large exoplanets that are in close proximity to their parent star. We know based on our own solar system that this composition is not conducive to creating the ideal environment for life. It is currently believed that to create a habitable planet, a solar system must have rocky planets such as Earth and Venus in the inner regions, with Jupiter-like gas giants orbiting further out.
The existence of life in our solar system has made it a template in the hunt for extraterrestrial life, and the existence of a gas giant beyond the orbit of Earth may have been a key factor in the evolution of our solar system, and the eventual formation of our home world.
Therefore, contemporary planet hunting techniques have not been ideal in furthering our search for extraterrestrial life. Since the current methods make it challenging for us to seek earth-like planets directly, it may be more beneficial to refocus our efforts in searching for other hallmarks of our solar system, such as Jupiter analogues, which we now know to be one of the building blocks necessary for the existence of an "Earth Mark 2."
In light of this, it is not surprising that the discovery of a gas giant with a similar mass to Jupiter, orbiting at almost the exact same distance as that separating our Sun and Jupiter has created some excitement in the scientific community. Another compelling element to the recent discovery is that the chemical signature of the distant star tells us that it is of a very similar composition and age to that of our Sun. The presence of Jupiter's twin hints at the existence of rocky inner planets of a similar structure to those in our own solar system.
The discovery was made using the HARPS instrument mounted aboard the ESO's 3.6-meter telescope located at the La Silla Observatory, Chile. The astronomers were able to detect the presence of the gas giant by observing a slight wobble in the motion of HIP 11915 as it is affected by the exoplanet's gravity. However, the team could not rule out the possibility that the Jupiter-like planet could be a phantom reading, and that the wobble could simply be caused by variations in the star's magnetic field.
Further observations will be required to confirm the discovery, however for now at least, HIP 11915 represents the best candidate to date for a solar system 2.0.
A research paper regarding the team's findings has been published in the online journal Astronomy and Astrophysics.
The video below shows an animation of Jupiter's twin orbiting HIP 11915.