Exoplanet Around Binary System Poses New Questions

Astronomers were recently able to discover a new exoplanet, which revolved around a binary system. Far from answering questions, the finding raised new ones, and casted doubt on established theories about how particular types of planets form.

The binary system the investigators were analyzing is located in the constellation Lyra, some 49 light-years away. The Jupiter-class extrasolar planet orbits the parental pair called HR 7162 at close range.

Experts found the gas giant is very close to the stars, and this posed additional questions as to how the planet was able to develop under such harsh conditions.

Space experts generally agree that the best way to explain how planets are formed in general is by slow accretion of material in the protoplanetary disk surrounding new stars.

These disks are basically fields of debris, made up of cosmic dust and gas, which are left behind after a star is born inside a nebula. The debris begins to spin around the giant fireball, and eventually clump together to form planets and other space objects over millions of years.

But such a formation process would have been impossible around HR 7162, experts say. This location would have made it impossible for the accretion disk to coalesce into something even remotely similar to a planet.

Gravitational forces are strong enough near a regular star, but a binary is not only producing immense pulls, but also turbulences and interplays that would have certainly ripped through a surrounding protoplanetary disk with ease.

But what the finding does support is an alternative theory on planetary formation, which holds that denser regions in the disks form the space bodies a lot faster, by collapsing under their own weight, under their own gravitational pull.

The investigators behind the new study also determined that the second method would produce a large exoplanet within only a few thousand years.

This is the maximum interval during which the stars would have allowed for a planet to be formed via accretion. But that process takes millions of years to compete.

The new study was carried out by astronomers at the Tennessee State University, who were led by expert Matthew Muterspaugh, Space reports.

The group published its discoveries in the esteemed Astronomical Journey, in a total of five research papers.