The planet has a high temperature.
Astronomers have discovered one of the most unusual at the moment exoplanets. It is a gas giant similar to our Jupiter, but located so close to its star that makes a complete revolution around it in just 1.5 days. As a result, the surface temperature of this planet is higher than most known stars.
The orbit of the planet lies near the star KELT-9, located approximately 650 light years from us. Scientists say that first encounter with the planet, wrapping so close to the star and having this level of temperature. Judge for yourself: surface temperature of exoplanet KELT-9b on the light side can increase up to 4600 degrees Kelvin. For comparison: the surface temperature of our Sun is about 5800 degrees Kelvin. But on mercury, the planet, is also very close to the star, the temperature barely reaches 700 degrees Kelvin.
The reason why the discovered gas giant there is a real hell is the fact that the star is very hot. Its temperature is about 10 to 170 degrees Kelvin.
“It is fair to say that this planet is hot at least 80 percent of the known stars. That in itself is just amazing,” says astronomer Jonty Horner from the University of southern Queensland (Australia) who have not participated in this discovery.
“At this temperature, the surface of the planet is more akin to the surface of its home star. The temperature and brightness of the star itself is much higher than that of our Sun. Overall this makes the hottest planet ever discovered by us. Its temperature more than 1000 K higher than the hottest planet discovered so far.”
Scientists have been able to find out some interesting details about this exoplanet. For example, despite the fact that KELT-9b is about 2.8 times heavier than Jupiter, it has half density compared to our gas giant. The reason is that the planet’s atmosphere is constantly blown away due to the strong activity of the native star.
“According to all definitions, based on the weight of the object is exactly a planet. But its atmosphere is not like any other, which was discovered any other planets. At least part of the huge temperature difference on its day side,” says one of the discoverers of KELT-9, the astronomer Scott Gaudi of Ohio state University (USA).
In fact, scientists are surprised by the fact that the planet is even able to withstand such intense heat.
“I’m truly surprised that this planet even exists. When you have such very massive and bright star, the power of its radiation is so great that it can actually blow the entire component of the planet matter. But for the formation of such planets in that region of space was not much gas and dust,” said the astronomer, Swinburne University of Technology Alan Duffy, who did not participate in the study.
These extreme conditions in which the planet has to be, is unlikely to allow her to survive for long, scientists say. According to estimates, the planet KELT-9b can lose every day, about 10,000 tons of its weight, which probably creates behind it a huge tail, which we usually used to see in comets.
Probably it will take not much time before the outer layers of the planet will be fully deflated under the influence of the stars, revealing a solid core (although not the fact that hard, as scientists still do not know which cores have a planet that is similar to the KELT-9b).
As noted by Horner, the study of the planet carried out in collaboration with an international team of researchers and Amateur astronomers, so scientists were able to conduct a truly challenging observation.
“We actually were able to push the boundaries of technological possibilities. The results of this work are really impressive,” said Horner in conversation with ScienceAlert.
Usually, scientists are trying to search for exoplanets around small, fainter stars like our Sun as they are easier to notice and to inspect for the possibility of having them near planetary objects. However, the observation of such a hot planet, KELT-9b, allows you to expand the boundaries of our understanding about what may be hiding in more difficult to learn systems.
“The results say that these super hot and super-bright stars can be of the world. Yes, as it turned out, so interesting,” says Duffy.
Now that scientists have discovered the existence of this wonderful world, they would like to explore in more detail KELT-9b using other telescopes. In this case, in their opinion, can help the new space telescope James Webb, that NASA space Agency plans to launch next year.