One of the low-density planets compared with Earth
NASA
A recent discovery of four planets orbiting a young star in our galaxy has piqued the interest of astronomers due to their incredibly low density, comparable to that of polystyrene. These planets could hold the key to unlocking the mysteries surrounding the formation of planetary systems.
Unlike most planetary systems in the Milky Way, which consist of larger Earth-sized planets or smaller Neptunes, this particular system is unique in that it features planets that are exceptionally light. The star, V1298 Tau, around which these planets orbit, is only 20 million years old, providing researchers with a rare opportunity to study the formation of planets in real-time.
Leading the investigation are scientists John Livingston from the Astrobiology Center in Tokyo, Japan, and Erik Petigura from the University of California, Los Angeles. By closely observing the orbital patterns of these planets over a five-year period, the team was able to calculate their masses and radii, revealing their remarkably low densities.
One of the challenges faced by the researchers was predicting the orbital periods of these planets accurately, especially for the outermost planet. However, their meticulous observations paid off, resulting in groundbreaking data that sheds light on the evolution of these unique worlds.
These low-density planets are currently undergoing a contraction phase, gradually forming into super-Earths or sub-Neptunes with radii comparable to Earth’s but masses only a few times greater. The orbital resonance exhibited by these planets aligns with existing theories on planetary system formation, further solidifying our understanding of how these systems evolve over time.
Sean Raymond, an expert from the University of Bordeaux, commended the discovery, stating that it offers valuable insights into the early stages of planetary system development. The presence of such young, low-mass planets orbiting a nascent star presents a rare opportunity to study a crucial transition phase in planetary formation.
