How to Make a Solar System

What the world’s largest telescope is revealing about the birth of planets

- VIVIANE FAIRBANK

ONE OCTOBER DAY a few years ago, astrophysicist Sean Dougherty opened an email to find an astonishing image. On his screen was a sunlike star located about 450 light-years away. Rendered in unprecedented detail, the bright yellow circle was surrounded by fuzzy rings darkening from orange to red with gaps interspersed in between. The whole thing looked like a hot element on an electric stove.

What Dougherty was seeing, for the first time in such fine resolution, was evidence of new planets forming.

The image had been created thousands of kilometres away, in Chile, by the largest ground-based telescope array in the world. At the time, the observatory hadn’t been fully completed, and astronomers were just starting to grasp the worlds it would open up to them. For Dougherty, who was then working as the director of a small observatory in Kaleden, BC, just south of Okanagan Lake, the image of the star, which is called HL-Tau, was almost too beautiful to believe. It hinted at what the solar system looked like in its infancy, more than four billion years ago. And, because it showed the dark gaps that astronomers had predicted in their calculations, it was a landmark in the history of astronomy.