internal Gas giant planet For researchers, this is still a mystery. Even for the planets in the solar system, it is extremely difficult to study their nuclei due to the difficulty of observation. In this case, exoplanets seem to have undergone an abnormal evolutionary process, providing scientists with a new way to understand the interior of the planet.
In this type of planet, there are in the so-called “Neptune Desert“The name means the scarcity of planets of different sizes between the Earth and Jupiter, and these planets orbit very close to their host stars.
In the few cases found, they are planets Unusually dense, Which indicates that they have experienced atmospheric erosion due to the high radiation from their host stars having partially eliminated their outer atmosphere. People think they are so rare because most of them eventually evaporate within billions of years.
In a study published today in the journal natural, A research team led by researchers David Armstrong From the University of Warwick (United Kingdom), Center for Astrobiology (CAB(CSIC-INTA), announced the discovery of one of the anomalous exoplanets called TOI-849b.
The discovery was made by TESS Space Telescope (Exoplanet survey satellite in transit) and confirmed by instrument Resin From European Southern Observatory (ESO) In La Silla, Chile.
Exoplanets orbit the solar system star TOI-849, approximately 730 light-years from the earth.his Radius, about 3.5 times that of the earthPoint out that this is a gaseous planet similar to Neptune and Uranus. However, when using the HARPS instrument to measure its quality, Unusually large massAbout 40 times that of Earth (Neptune is about 16 times the mass of Earth).
The radius and mass values of TOI-849b indicate that its density is similar to that of the Earth, so it is a huge solid planet, the largest solid planet discovered so far, containing up to 3% of its mass as a gaseous atmosphere.
With these unique characteristics, the researchers’ main hypothesis is that we are in front of the naked core of a natural gas giant like Jupiter, but have evaporated all of its gaseous envelope.
In order to explain this huge loss of quality, the researchers proposed Various situations.In one of them, the planet originally formed as a gas giant Away from the star and then migrate inland And it is so close to the star that the atmosphere disappears due to tidal action.
Another possibility is Large planet collision With another planet in the system. It is even possible that TOI-849b is also a failed giant: after its nucleus is formed, something may happen in the system, which prevents the planet from accumulating the gas needed to form the atmosphere.
But is this the only possibility? One of the tasks of the CAB co-authors is to rule out other possible situations.especially in TROY projectLed by CAB researchers Jorge Lillo-Box, It has been evaluated that the stellar wobble measuring the mass of a planet is not caused by one planet, but by two planets in the same orbit (called co-orbiting planets).
Bare rock core
As Lillo-Box pointed out, “The analysis performed makes it possible to exclude planets that orbit with TOI-849b and have masses greater than eight Earth masses. These results can definitely rule out the source of planetary masses in orbiting scenarios. , Thus confirming the following hypothesis: TOI-849b is definitely a bare rock core, it is likely to be A huge sphere mainly composed of iron and silicate“.
Therefore, TOI-849b represents a unique situation in which the material of primitive atomic nuclei formed by gaseous planets can be studied. The authors say that this discovery will enable people to better understand the internal structure and formation of the gas giant.
In any case, the origin of this strange planet has yet to be determined, and further observations will be necessary in the future to clarify its origin.
This European Space Agency The planned launch of a mission similar to TESS, but much larger, including the National Institute of Aeronautics and Astronautics (INTA) and CAB, as well as other institutions in Spain, such as the Institute of Astrophysics of Andalusia, the University of Granada and the Institute of Ghana The astrophysics of the Lee Islands plays a very important role.
its about PLATO satellite, Currently under development. Its mission is to detect and identify Earth-type planets in orbits around stars similar to the sun. This is a critical moment for its design and implementation. According to its initiators, it needs the firm support of the National Research Agency and the Spaniards. Technology Development Center.
in order to David BarradoThe CAB researchers who participated in the study said: “Take TOI-849b as an example. The results of the TESS satellite show that over time, decisive and coherent investment will lead to significant progress in our understanding of the universe and the reality of the universe. . Our role in it”.
DJ Armstrong, TA Lopez, V. Adibekyan, RA Booth, EM Bryant, KA Collins, A. Emsenhuber, CX Huang, GW King, J. Lillo-Box, “Remnant Planetary Core in the Neptune Desert” proposed by JJ Lissauer, EC Matthews, O. Mousis, LD Nielsen, H. Osborn, J. Otegi, NC Santos, SG Sousa, KG Stassun, D. Veras, C. Ziegler, JS Acton, JM Almenara, DR Anderson, D. Barrado and others. natural, 2020. https://doi.org/10.1038/s41586-020-2421-7