Comets Orbiting Sun-like Star Discovered Outside The Solar System

For the first time in the history of astronomy, scientists have found evidence of a comet, outside of the solar system, revolving around a sun-like star. This milestone has been achieved by an international team of researchers.

According to the researchers, these icy comets, or exocomets, are placed at a distance of about 160 light years from Earth. The researchers did not observe the comet directly at first, but they made use of European Space Observatory's ALMA radio telescope. Using ALMA, the researchers were able to measure small amounts of carbon monoxide in the debris disk around the star.

A debris disk is mostly found around all types of stars, both new and old. It differs from what is called a protoplanetary disk. While both are formed of dust and debris, a protoplanetary disk forms around young stars only and has the capability to give rise to new planets. Debris disks are formed as a result of collisions between large bodies during the protoplanetary disk phase.

The researchers specifically looked at the debris disk and protoplanetary disk system around a star dubbed HD 181327. The team specifically chose this star because it appeared a lot dusty to them, suggesting the greater probability of collisions.

The team figured out that the star was just 23 million years old and was 30 times larger than the sun in terms of size. The presence of carbon monoxide in the ring was later confirmed with the help of ALMA, and the researchers suspect that the gas is probably released because of collision between the icy comets, along with dust.

The researchers thus believe that the same phenomenon leads to the production of gas and dust. There could be other explanations as well, but the simple one is to believe that the gas and dust are being released by the exocomets, that is, icy bodies.

The complete details of the discovery are scheduled to be published in Monthly Notices of the Royal Astronomical Society.