How Can Some Planets Get Hotter Than Stars?


A new study published in The Astrophysical Journal Letters answers some of the curious questions about exoplanets and hot Jupiters. The study also offers suggestions for how planets in the extremely hot Jupiter class such as Celtic-9b could have formed.

Until the early 2000s, the only known planets were In the solar system were located. These planets were broadly divided into two categories: The Inner Sun rocky planets in the system and outside cold gas giants. With the discovery of exoplanets orbiting stars other than the Sun, different planetary classes were discovered and a new picture began to emerge.

Data from the Kepler mission, for example, revolves around the gas-made exoplanets orbiting very close to their stars. 727 degrees Celsius showed that it had reached temperatures exceeding it. These planets “hot” or “extreme heat” Jupiters and although most of these have dimensions between Neptune and Earth, we don’t know much about their composition.

So how can hot, gaseous planets form and exist so close to their stars? What kinds of extreme physical processes are taking place here? The answers to these questions have a huge impact on our understanding of the exoplanets and Solar System planets. The Astrophysical Journal Letters’da In the latest published work, another piece is added to the puzzle of planet formation and evolution.



Hot Jupiters actually extreme physical and chemical processes is a window that opens. Studying them can greatly improve our understanding of chemical and thermal processes, atmospheric dynamics, and cloud formation.

We are still trying to explain how planets are formed and how elements such as water are transmitted to our own solar system. To understand this, by observing the atmospheres of other planets chemical composition we need to learn more about it.

Observing atmospheres

Hot jupiter

There are two main methods for studying exoplanet atmospheres. ‘Transition’ In the method, we can capture starlight filtering through the atmosphere of the other planet as it passes in front of its star, and reveal fingerprints of any chemical element present there.

Another method of researching a planet is that its star is passing behind it. ‘eclipse’ is during. Planets also emit and reflect a small portion of light, so we can infer light from the planet by comparing small changes in total light when the planet is hidden and visible.

Both types of observation in different wavelengths or colors, and as chemical elements and compounds are absorbed and spread at very specific wavelengths, it is a form that will make sense of the composition of the planet’s atmosphere. spectrum can be produced.

Secrets of Celtic-9b


As part of the study, the researchers eclipse spectrum used images recorded by the Hubble Space Telescope to obtain it. As a result of the investigations, a large amount of metal was found. This discovery is interesting because it was previously thought that these molecules could not be found at such extreme temperatures.

Celtic-9b is subjected to the strong gravitational force from the star around which it rotates; this too ‘gravity lock’ which causes the same face of the planet to be constantly facing the star. Therefore, there are strong temperature differences between the day and night sides of the planet.

While the researchers investigated the warmer side with eclipse observations, the observed molecules were actually from colder regions that are not facing the star or that the interior of the planet could be drifted deeper by dynamic processes. These observations show that the atmospheres of these extreme worlds are governed by complex processes that are little understood.

Another thing that makes Celtic-9b interesting is that it is about 80 degree inclined orbit. This points to a violent past full of possible collisions and actually occurs on many of the planets in this class. Researchers say that this planet formed away from its main star could be and he thinks the collisions may have occurred as he migrated towards the star. This supports the theory that massive stars tend to form in protostar discs that trap gaseous and solid materials as they migrate towards their planets, away from their parent stars.