Astronomers have for the first time mapped gases in three dark rings around a distant star. The rings mark spaces where planets are thought to have formed from dust and gas around the star.
“The inner gap is mysterious. Whatever is creating the structure is removing the dust but there’s still a lot of gas.”
All the rings around HD 163296 are devoid of dust, and researchers are sure that planets, probably gas giants with masses comparable to Saturn, are responsible for clearing the outermost ones.
But the inner ring has far more carbon monoxide than the other two, leading them to believe no planet exists there. That remains unexplained, says astronomer Andrea Isella of Rice University, who led the international team.