Discovery of a very large planet “TOI-5205b” that theoretically should not exist | Sorae Portal site to space

The smaller the star’s mass, the more abundant it is in the universe. A photosynthetic star has a low surface temperature and emits a lot of visible red light.red dwarfIt is called. Red dwarfs are numerous, so they revolve around red dwarfsexoplanetoften found. However, exoplanets orbiting red dwarfs tend to be of lower mass, especially compared to Jupiter.gas giant‘ Not found.

The reason red dwarfs do not have gas giant planets is believed to be related to the process of star and planet formation. Dust and gas in space are attracted to each other by gravity, and matter is concentrated in the high-density regions. In places where matter is most concentrated, stars are eventually born. Then, the surrounding material collects around the part where the star was born, forming a rotating disk. Matter locally concentrates in this disk, and countless minor planets are born. Small planets combine to form planets, and at the same time, they collect surrounding gases and become enveloped in the atmosphere.

When a star is born at the center of the disk, the radiation from the star creates a force that pushes the dust and gas that make up the disk outward, limiting the amount of time the planet’s body and atmosphere grow. Also, the smaller the mass of the disk as a whole, the less material there is for stars and planets, so stars and planets born tend to be smaller. According to the current theory of planet formation, in order for a gas giant the size of Jupiter to form, a rocky planet with a mass of about 10 times that of Earth would have to be born, and it would require enough gas and time to cover it as an atmosphere and it is believed that it was previously believed that none of these conditions were met during The formation process of a red dwarf.

A research team led by Shubham Kanodia at the Carnegie Institution said:TOI-5205And a new outer planet.TOI-5205bFind out. TOI-5205 was first listed by NASA’s Transiting Exoplanet Survey Satellite (TESS) as a candidate for a star with a planet. It became confirmed.

What is surprising is its size. TOI-5205b is estimated to be roughly the same size as Jupiter in terms of diameter and mass. On the other hand, TOI-5205, the star around which TOI-5205b orbits, is a small star with a diameter and mass of about 40% of that of the Sun.The diameter of TOI-5205b to TOI-5205 is about 27%. Given that Jupiter’s diameter is only about 10% that of the Sun, you can see the enormity of this planet. Because of this, when TOI-5205b intersects in front of TOI-5205, approximately 7% of the light from TOI-5205 that reaches Earth is blocked.

【▲ Fig. 2: Size comparison of TOI-5205 (top left), TOI-5205b (bottom left), the Sun (top right), and Jupiter (bottom right). Because TOI-5205b and Jupiter are roughly the same size, the ratio to TOI-5205, a star smaller than the Sun, is relatively large[Credit: Katherine Cain, courtesy of the Carnegie Institution for Science]]

More important than the diameter is the mass ratio.The mass ratio of TOI-5205b to TOI-5205 is about 0.3%, which is much larger than the approximate 0.1% mass ratio of Jupiter to the Sun. In fact, this value is the largest for a planet in a red dwarf. The existence of such planets cannot be predicted by conventional planet formation theory. Given the mineral content

For TOI-5205, there is currently no possibility of an exceptionally large planet forming. As such, the existence of TOI-5205b calls into question our current understanding of planet formation.

*…the term “metal” in planetary science refers to all elements other than hydrogen and helium. A star with a high metallic content means that there are many heavy elements such as silicon and iron, which are the materials of the planets. However, because TOI-5205 contains about the same amount of metal as the Sun, it does not have the conditions for planet formation.

On the other hand, TOI-5205b produces significant attenuation when traversing TOI-5205. At this time, some of the star’s light passes through the planet’s atmosphere, and analysis of this light reveals the exact atmospheric composition of TOI-5205b. This would be a great clue about the formation of planets. Additional observations of TOI-5205b, both on Earth and in space, are expected.

• source Shubham Kanodia et al.
• “TOI-5205b: A Short Period Jovian Planet Passing a Medium-Size Dwarf”. (The Astronomical Journal) Washington, DC.

A ‘forbidden’ planet orbiting a young star challenges theories of gas giant formation.” (Carnegie Institution for Science)