On January 15, 2022, website Encyclopedia of extrasolar planets It was reported that 4.921 outer planets It was known to mankind. This is only the beginning even if we think we have already made extraordinary progress since the discovery of the first exoplanets in orbiting Around’stars on celebrity main sequence, in 1995 (we already knew the state of two exoplanets around A pulsar, PSR B1257 + 12, since 1992).

We know that the Swiss Michel Mayor and Didier Queloz It was revealed for the first time that the existence of Hot Jupiters, From gas giants Closer to the host stars for them Mercure from the sun. This was a surprise, although some theorists of planetary genesis had already considered migration processes early in the history of exoplanet formation. We will see why, a little later, it was necessary to assume these processes.

These stars were initially discovered using Radial velocity method (See on this topic one of the videos from the CEA series below) on Earth but the great harvest was done mainly by devices in orbit using the method Transit Planets with the Kepler satellite and today with his successor he-goat (Transiting a satellite to survey the outer planets). We are of course mainly interested in discoveringexoterres, From rocky planets of size and mass so close to that of Earth that it would be in orbit at habitable area Sun-like star or a lips of a woman. Let us remember that the question of defining the habitability zone is not a simple one, more than it is of relevance to chasing extroverts around red dwarfs for exobiology questions..

Hot Jupiters to understand the dynamics of planetary systems

However, the discovery of exoplanets other than exoplanets also brings its share of important information toAstrophysics and theexobiology We are also preparing to try to do it thanks to the telescope instruments James Webb, chemical composition analyzes ofambiance From hot Jupiters, such as WASP-62b, more than those around the outer planets like those around it Trappist 1.

The theory tells us, beyond a reasonable doubt, that gas or ice giants form at great distances from young stars in the protoplanetary disk that surrounds them at birth. So the hot Jupiters migrated, and with that, their field migrated gravity It affected the rest of the planetary composition.

Making statistics on the chemical composition of these celestial bodies and their presence in planetary systems thus informs us about the general process of cosmogony of the outer planets of the world. Milky Way And therefore, Fine, on the chances of the existence of habitable exoplanets in our area galaxy. Here is what to select famous landmarks Drake equation For Seti in particular.

Today, a team of researchers published in Astronomical Journal open access article about arXiv that announces discovery by he-goat of three hot planets around giant or giant stars that are short Tropical periods And the fate imposed by celestial mechanics on such stars. Samuel Grunblatt, Postdoctoral Researcher atAmerican Museum of Natural History and on Flatiron Institute New York, explains them that ” These findings are essential to understanding a new frontier in exoplanet studies: how planetary systems evolve over time. These new notes are introduced windows On end-of-life planets, before their host stars can swallow them ».

In fact, it was initially cleared as candidates for the title of an exoplanet in the Tess data, and the presence of TOI-2337b, TOI-4329b And TOI-2669b It was confirmed by instruments at the WM Keck Observatory on top of Maunakea in Hawaii. However, they seem doomed in the short term by the cosmic time scale. in case if You are -2337bIt will continue its migration to the point of ingestion in just a million years.

The end of the life of the solar system?

So we are in front of laboratories that can give us new ideas about how our sun swallows the planets in several billion years in stages. red giant. some astrophysicists I assumed that indawn from formation solar system He might have swallowed at least one Superterry.

What we already know is that these three exoplanets have masses between 0.5 and 1.7 times the mass of Jupiter and range in sizes from slightly smaller to more than 1.6 times the size of Jupiter. They also cover a wide range of densities, ranging from moss From polystyrene To it is three times higher than water, which indicates a variety of origins, and therefore, as we have said, valuable evidence for the origin of the planetary universe in the Milky Way.

What we also know is that, as in the case of a file Hot Jupiter Discovered in 1995, 51 Pegasi B, they orbit solar-type stars that are already several billion years old and that, according to another author of the discovery, Nick Saunders, it is expected ” Dozens to hundreds of these advanced transiting planetary systems found with Tess, providing new details about how planets interact with each other, swell and migrate around stars, including those similar to our Sun His colleague and co-author Daniel Huber points out that “ Keck’s observations of these planetary systems are key to understanding their origins, helping to reveal the fate of solar systems like ours. ».

If, as we have already said, TESS has expelled these planets by a photometric method that gives the radius and orbital period of these planets, then it would require confirmation of their existence by spectroscopic analysis, via the spectrometer at height Precision Designations that made it possible to use the method of radial velocities and stabilization of the mass, and therefore the density of these stars.

Planetary scientists have reason to believe that the great variety in densities that have been found indicates that these planetary systems were formed through chaotic interactions between exoplanets. In fact, models developed using celestial mechanics to account for such systems not only mean that giant planets must move toward their host stars as the stars evolve over time, especially in the last 10 percent of Duration The life of the star, but also that this stellar evolution, with a loss of mass or bulge, can cause the orbits of the planets around the host star to converge, increasing the likelihood that some of them will enter into collision.

As the version of the Keck observatory shows, the TOI-4329 – in particular – is intriguing. Like all exoplanets that can fall into the grid stretched by TESS, it must be in a sphere with a radius of 200 light-years at most. This means that its atmosphere can be analyzed, at least in part, using Spatial Telescope James Webb Which can detect the presence of water or satiate, and more generally data that would provide constraints on where these planets formed and what interactions should have taken place in the orbits of the planets we see today.