Over the last two and a half decades, more than 4000 exoplanets have been discovered by scientists. One of the classes of planets that are still quite a mystery to scientists are known as “hot Jupiters.” This particular type of exoplanet is similar in size to Jupiter but orbit extremely close to their parent stars.
Some planets of this type can orbit their host are in as little as 18 hours. To learn more about this type of exoplanet, scientists have turned to studying a more recently discovered hot Jupiter called HIP 67522 b. This planet appears to be the youngest hot Jupiter ever discovered, and it orbits a well-studied star about 17 million years old.
Scientists believe that HIP 67522 b is only a few million years younger than its parent star. While that ancient by human standards, most hot Jupiter planets are more than a billion years old. HIP 67522 b orbits its host star about every seven days. That host star has amassed similar to the and is located about 490 light-years from Earth.
The planet is about ten times the diameter of Earth, and its size indicates that it is a gas-dominated planet. HIP 67522 b was defined as a planet candidate by NASA’s TESS observatory that detects planets via the transit method. Scientists say the discovery of HIP 67522 b offers hope of finding more young hot Jupiter planets and learning more about how they form throughout the universe.
Currently, scientists have three main theories for how hot Jupiter planets get so close to the parent stars. One suggests that they form there and never move. Another theory suggests that hot Jupiter planets migrate inward from further out in the solar system. Another major theory suggests that the planets get close to their stars later in life when the gravity of other planets around the star can drive planetary migration.