We cannot yet directly image young planets around AU Mic, but they cannot completely hide from us either, says study author Michael Liu of the University of Hawaii's Institute for Astronomy. They reveal themselves through their gravitational influence, forming patterns in the sea of dust grains orbiting the star. Liu used the Keck II Telescope to study the 12-million-year-old red star. Instead of appearing symmetric, the disk encircling AU Mic is uneven, with clumps that arise through interactions with the gravity of accompanying planets. The clusters are far from AU Mic, lying between 25 and 40 astronomical units away, about the same distance as Neptune and Pluto are from our sun.
The new data do not reveal what types of planets could be present, but suggest that they travel in elliptical orbits. By studying very young stars like AU Mic, we gain insight into the planet formation process as it is occurring, Liu says. As a result, we learn about the birth of our own solar system and its planets.