A Team Led by a Ukrainian Scientist Discovered a New Exoplanet

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It would seem nothing special, the discovery of new exoplanets is not something extraordinary. However, this event is significant and important for everyone interested in space.

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What exoplanet was discovered?

Meet Olga Zahozhai, a Ukrainian astrophysicist. In her homeland, the press sometimes called her an "exoplanet hunter." With the beginning of the war, it was impossible to continue her work in Ukraine, so she left for Germany. There, a team of scientists, under her leadership, continued the search for new exoplanets.

They managed to discover an exoplanet, which was named HD 114082b. The results of this study were published in the journal Astronomy & Astrophysics on November 25, 2022.

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The new exoplanet is a 15-million-year-old super-Jupiter. HD 114082 b was found to orbit its star for 110 days at a distance of about 0.5 AU.

Why Is This Important?

HD 114082b is the youngest exoplanet for which a radius and mass have been determined. Despite the fact that its size corresponds to the diameter of Jupiter, its mass is eight times greater. Such parameters of the planet do not agree with accepted models of planet formation. It is likely that the new planet, which is a gas giant, has an unusually large solid core.

Compared to known gas giants, HD 114082 b is about two to three times denser. This is especially surprising, considering its relatively young age - 15 million years. For example, its average density is twice that of the Earth. This is actually an amazing fact because Earth is a rocky planet with an iron-nickel core. The most studied gas giant, Jupiter, is composed of hydrogen and helium, the lightest elements in the universe.

The discovery of the exoplanet HD 114082 b shows us that, in fact, we know almost nothing about space and the processes of formation of cosmic bodies. We rely on our own assumptions, which are probably far enough from the truth.

How Do We Iimagine the Formation of Giant Planets?

Scientists now believe that giant planets can form in two possible ways. Both of these processes occur inside the protoplanetary disk of gas and dust distributed around the young central star.

The first process is called "core accretion". It consists in the accumulation of a hard core of stony material. When this core reaches a critical mass, its gravity begins to pull in the surrounding gas. As a result, accretion of hydrogen and helium occurs in an accelerated process with the formation of a giant planet.

The second process is "disk instability". In this case, there are gravitationally unstable regions of dense gas that collapse into a giant planet without a rocky core.

It seems that HD 114082 b does not meet the expectations of astronomers. The combination of its mass and size is incompatible with the picture of a hot start. Instead, it seems to fit the cold start scenario better.

Conclusion

HD 114082 b is not the only young gas giant that does not fit the hot start model. There are two more planets younger than 30 million years with known masses and sizes. However, HD 114082 b is the youngest.

We can already say that Olga Zahozhai's discovery has added work to theorists, who are now forced to reevaluate their models. And this is certainly the most significant space discovery of Ukrainian scientists in 2022.

Sources:

• Astronomy & Astrophysics
• Mezha