Myriam Benisty

Around the star HD 163296, 330 light-years away, a dense ring of gas and dust is swirling. Astronomers have spotted a small but bright patch of hydrogen cyanide and ethynyl molecules within it. It hangs at a distance of 88 astronomical units from the star — farther than Pluto is from the Sun. The heat from a forming planet hidden in that patch melts the icy dust.

The young star PDS 66 is surrounded by a flat disk of gas and dust — the cradle of future planets. In the cold outer regions of such a disk, silicon and sulfur are usually hidden inside dust grains, but astronomers spotted a bright patch of gas at about 60 astronomical units from the star.

The star AB Aur is young, about 4 million years old. Around it swirls a dense disk of gas and dust. Recently, a long gas stream, a flow of material from the surrounding cloud, crashed into it.