As we began to discover hundreds and thousands of exoplanets, we discovered that there were two types of worlds unlike anything else in our solar system. First is the super worldAnd. These worlds are on the border between large rocky worlds like Earth and small gas planets like Neptune. The second is hot Jupiters. Large gas giants orbit their stars in a few days.

While there may be a super-Earth lurking at the outer edge of our solar system, we know that our Sun is not a hot Jupiter. This is somewhat surprising because gas giants in close orbit seem to be a fairly common occurrence. But a new study published on the arXiv preprint server may explain why there are no Vulcans in our solar system.

One of the reasons why hot Jupiter exoplanets are so common is systematic error in observations. Large planets orbiting small stars are the easiest type of planet to detect, so it’s natural that we find lots of them. But over the years we’ve gotten better at finding lots of planets, and hot Jupiters are still common, especially around red dwarfs. But they are less visible around stars like the Sun, and the authors of this study wanted to find out why.

So they examined a sample of 382 sun-like stars from the California Heritage Survey. This research includes spectroscopic data so the team can look at factors such as the stars’ metallicity and age. Of this sample, 46 contained gas giant planets; The team divided these into hot Jupiters (orbital periods in order of days) and cold Jupiters (orbital periods in order of years).

For starters, unlike red dwarf planets, there were more cold Jupiters than hot ones. The team noticed that young stars were more likely to have hot Jupiters than older stars. So they used their samples to create a Bayesian model of hot Jupiters orbiting Sun-like stars. They found that the statistical numbers drop off in the middle of a star’s life, around 6 billion years old.

This says that the orbits of cold Jupiters remain stable for billions of years, while the orbits of hot Jupiters do not. It appears that the orbits of hot Jupiters eventually become unstable and eventually get absorbed by their stars. As a result, hot Jupiters are rare among old sun-like stars.

Since our Sun is still in the early middle ages, it is unlikely that it once had a hot Jupiter and was swallowed by it. We have no evidence of a hot Jupiter in our solar system. But if it had been present in our Sun’s youth, it could have cleared out smaller worlds that were too close to the Sun. At least we now know that hot Jupiters, although common, are rare around middle-aged stars like our Sun.

The study also shows how unusual our solar system is. Stars like the Sun are relatively rare, and most planets orbit red dwarfs. As we continue to find planetary systems, we may one day find several star systems more similar to ours and better understand not only hot Jupiters, but also the wide variety of planets there may be. Source