Researchers spot whirlwind marking possible exoplanet in the making

A visualisation showing concentrations of warm dust and pebbles orbiting in a cloud around the star HD 163296 where an exoplanet may be in the process of forming. Image: J. Varga et al.

Astronomers using the European Southern Observatory’s Very Large Telescope have spotted a concentration of warm dust and pebbles in a Mercury-like orbit around a star 330 light years away that may indicate the formation of a new planet.

The presumed exoplanet in waiting orbits the star HD 163296 where researchers previously found evidence for the formation of three large planets in a wide orbit.

Using the MATISSE instrument to combine and analyse light from the VLT’s four-telescope array, a team led by Jozsef Vargo of Leiden University focused on the inner region of a broad ring of warm, dusty debris orbiting the star and found one part of the disc was much brighter, or hotter, than the rest.

The “hot spot” orbits the star at roughly Mercury’s distance from the Sun, taking about one month to complete one revolution. The researchers plan future observations of additional stars with dust discs to learn more about exoplanet formation with an emphasis on those in which Earth-like planets might form.