Atacama Large Millimeter/submillimeter Array (ALMA) has spotted a young star named HD 163296 and according to astronomers this ringed star is home to at least two newly forming planets.
The star is located 400 light-years from Earth and at twice the mass of our Sun, is believed to be roughly 5 million years old. Using the ALMA’s ability to detect the faint millimeter-wavelength “glow” emitted by gas molecules, Andrea Isella, an astronomer at Rice University in Houston, and colleagues studied HD 163296 claim to have found compelling evidence that there are at least two newborn planets, each about the size of Saturn, orbiting the star.
According to the study published in Physical Review Letters, the two planets are still not fully formed and are located at a distance of 100 AU and 160 AU from the central star. An astronomical unit — AU — is the average distance from the Earth to the Sun. This means that the two planets are very far from the central star – well beyond the extent of our solar system’s Kuiper Belt, the region of icy bodies beyond the orbit of Neptune.
The astronomers have claimed existence of two planets based on an appreciable dip in the amount of CO in the outer two dust gaps. By seeing the same features in both the gas and the dust components of the disk, the astronomers believe they have found compelling evidence that there are two planets coalescing remarkably far from the central star. The width and depth of the two CO gaps suggest that each potential planet is roughly the same mass as Saturn.
In the gap nearest to the star, the team found little to no difference in the concentration of CO gas compared to the surrounding dusty disk. This means that the innermost gap could have been produced by something other than an emerging planet. Researchers say that while it is certainly possible that the ringed structures around the star are the result of a nascent planet plowing through the dust, they do not rule out possibilities of something else that would have done this; however, the new observations using ALMA provide intriguing evidence that planets are indeed forming around this one young star.