200-Million-Year-Old Star System Observed
Astronomers observed a planetary system in its "teenage" years for the first time — 200 million years old and still forming. The system provides a window into how radiation strips young planets and influences their formation or destruction, marking a major advance for astrophysics.
The star at the center of this observation is V1298 Tau, located about 350 light-years from Earth. It is exceptionally young, estimated to be between 20 and 30 million years old—a mere infant compared to our 4.5-billion-year-old Sun. This system contains four known planets, all larger than Earth, ranging in size from Neptune to Jupiter. The planets orbit so closely to their young, active star that they are bathed in intense X-ray radiation, a torrent that could be 10,000 times stronger than what our own sun emits. This fierce radiation is literally boiling away the atmospheres of the innermost planets. This process, known as photoevaporation, is predicted to strip the gassy outer layers from these "mini-Neptune" worlds, eventually leaving behind dense, rocky cores known as super-Earths. Observatories like the Hubble Space Telescope and the Chandra X-ray Observatory were used to study this atmospheric stripping in action. By catching this process, astronomers are witnessing a key phase of planetary evolution for the first time, providing a direct look at how the most common types of planets in our galaxy are formed and transformed.
