'Hot Jupiters' Can Grow In Size As They Age, Claim Scientists
Over the last few years scientists have discovered many exoplanets by detecting dips in light as these orbit their own star.
Now, a new study reveals that "hot Jupiters" - exoplanets that have a short star-planet distance - will continue to increase in size as time progresses.
For the uninitiated, hot Jupiters are a class of exoplanets that have a mass and radius almost similar to that of Jupiter in our solar system. However, these exoplanets are a lot hotter than our Jupiter.
These exoplanets are much closer to their parent star and, therefore, have a very short orbital radii compared to our gas giant. These planets have no counterparts in the solar system.
The New Theory
In the last two decades, scientists have found the existence of 3,400 worlds apart from our solar system. Their observations revealed the existence of hot Jupiters that have a shorter distance when compared to the one between Mercury and the sun.
"The size of a gas giant planet is primarily set by the heat in the deep interior of the planet, and since these planets are not generating [new] heat internally, you would expect them to cool and contract over time. The only way they can be getting bigger over time is if some of the radiative energy from the star is somehow making its way deep into the planet and heating it," says Joel Hartman of Princeton University, the lead author of the study.
In order to simplify this mystery, researchers evaluated two newly discovered hot Jupiters. One of them is dubbed HAT-P-65b, while the other has been named HAT-P-66b.
Hartman added that hot Jupiters grow bigger as they get older. However, researchers still do not have any substantial proof to support the hypothesis.
The researcher also revealed that he would be keen on observing if other massive gaseous planets on wider orbits, like Jupiter in our galaxy, are able to become tremendously inflated when the host or parent star heats them up substantially.
Hot Jupiter Discoveries
Currently, nearly 300 hot Jupiters has been discovered. However, the most astounding discovery is the fact that one of these exoplanets has two close-in planetary companions instead of one.
The discovery is quite thrilling and has the scientific community excited. Juliette Becker, a student of University of Michigan, summed it up when she said that researchers have delved into existing data for these exoplanets for decades but not made any substantial breakthrough. This was taken to believe that having close-in planetary companions was not plausible. However, the current discovery bears testimony to the fact that it is possible.
While one cannot spot hot Jupiters with the naked eye, there are a few super telescopes that are able to pick them up.