Astronomers have discovered a young planet undergoing a rapid transformation. Named TOI 1227 b, this infant world is being bombarded by intense X-rays from its host star, stripping away its thick atmosphere
The discovery was made using NASA’s Chandra X-ray Observatory and shows us how planets evolve in their earliest years.
TOI 1227 b orbits a small red dwarf star called TOI 1227. Despite the star being much less massive and cooler than our Sun, it is blasting out powerful X-rays that are harming the nearby planet. This relentless radiation is expected to continue for millions of years, gradually shrinking the Earth into a smaller, more compact world.
With TOI 1227 b being only 8 million years old, it is one of the youngest planets ever discovered in transit, a phenomenon where a planet passes in front of its star from our point of view.
Earth is nearly 5 billion years old. Currently, the young planet has a mass about 17 times that of Earth and a diameter roughly equal to that of Jupiter. However, astronomers believe that over the next billion years, it could lose an amount of mass equal to two Earths.
This dramatic loss is being driven by the planet’s proximity to its host star, less than one-fifth the distance between Mercury and the Sun. In such a tight orbit, TOI 1227 b receives a constant and intense dose of X-rays. Computer models indicate that these high-energy rays are stripping the atmosphere away at a rapid rate, with the planet losing the equivalent of Earth’s entire atmosphere roughly every 200 years.
A harsh environment
The conditions on TOI 1227 b make it extremely unlikely for life as we know it to exist. The planet lies far outside what scientists call the “habitable zone”, the range of distances from a star where liquid water could potentially exist on a planet’s surface. Its extremely close orbit and swollen atmosphere, heightened by the radiation it endures, create a harsh and volatile environment.
Although its exact composition is not fully understood, TOI 1227 b is thought to be similar in mass to Neptune but significantly larger due to its inflated atmosphere. As time goes on, this planet may shrink to about one-tenth of its current volume as it continues to lose material.
A look into planetary evolution
TOI 1227 b is unique not only because of its youth but also because of its slow orbital period compared to other known young exoplanets, as well as its low-mass host star. These factors make it an essential object of study for astronomers seeking to understand how planetary systems form and evolve.
Researchers used several methods to estimate the planet’s age, including measuring the movement of its host star relative to nearby stellar populations and comparing its brightness and temperature to models of young stars. Their findings suggest that TOI 1227 b is in a crucial stage of planetary development, offering a rare glimpse into how extreme environments shape the future of planets.
