If the New Planet is there, a large and mysterious planet hiding at the dark edges of the Solar System, it may not be where I thought it might be.
According to astronomers looking for the hypothetical object, the new information considered could mean that its orbit is significantly more elliptical than most recently predicted.
The hypothetical New Planet made a big comeback in 2016, when astronomers Konstantin Batygin and Michael Brown of Caltech published a paper in Astronomical Journal. In it, they set out their case for a planet still undiscovered in the outer edges of the solar system. The evidence, they said, is in other objects beyond Neptune’s orbit.
These objects are called Extreme Trans-Neptune Objects (ETNOs). They have huge elliptical orbits, which never cross closer to the Sun than Neptune’s orbit at 30 astronomical units and swing more than 150 astronomical units.
Batygin and Brown discovered that these orbits have the same angle at the perihelion, the point in their orbit closest to the Sun. Astronomers performed a series of simulations and discovered that the gravitational influence of a large planet could group orbits in this way.
Since the fall of the work, the theory has become very controversial, with many astronomers considering the existence of the New Planet unlikely, but so far we have no firm evidence in one way or another. The most conclusive way to resolve the debate is to find the slippery slope – and a new update from Batygin and Brown could help us try to do just that.
Their new work was accepted in The Astrophysical Journal Letters, and is available on the arXiv prepress server.
The initial detection of a possible New Planet in 2016 was made on the basis of only six ETNOs – these objects are, after all, very small and very difficult to detect. Over time, several ETNOs have been discovered – today we know about 19 – which means that we now have more data to analyze to calculate the characteristics of the planet.
In 2019, astronomers reviewed the available information and concluded that they had obtained some slightly incorrect things. The mass of the planet, according to the revision, was only five times the mass of the Earth, rather than the one they had initially calculated, and its eccentricity – how elliptical it is – was smaller.
And now they have updated these calculations again.
“However,” they wrote in a post on the Find Planet Nine blog, “the question we asked ourselves during the pandemic is a different one: are essential physics missing from our simulations? Through our continuous and incessant survey of the model, we discovered that the answer to this question is “yes”. “
Their simulations, they said, assumed that any object moving beyond 10,000 astronomical units from the Sun is lost in space. Which did not take into account the fact that the Sun was not born in isolation, but probably in a large, heavily populated cloud, which forms stars, along with other baby stars.
Under these conditions, the baby Solar System would almost certainly have formed an inner section of the Oort Cloud, the shell of the frozen bodies that surround the Solar System between about 2,000 and 100,000 astronomical units from the Sun. The formation of giant planets, such as Saturn and Jupiter, would have thrown debris out into interstellar space; but the gravitational perturbations of the passing stars would have pushed them back into the gravitational influence of the Sun, so that they would form the inner Oort Cloud.
We tend to think of the Oort Cloud as a kind of hanging, which really doesn’t do much of anything, but when Batygin and Brown ran a bunch of new simulations, considering these physics, they found that the objects in the inner region of the Oort cloud can move really little.
“The New Planet, however, is changing this picture on a qualitative level,” the researchers said.
“Due to the long-term gravitational pull of the New Planet’s orbit, the inner objects of the Oort Cloud have been evolving on billions of years, being slowly reinjected into the outer solar system. So what happens to them? We simulated this process, considering that perturbations from the canonical giant planets, the New Planet, the passing stars, and the galactic wave and found that these objects inside the reinjected Oort cloud can easily mix with the census of distant Kuiper belt objects and even present orbital agglomerations. . “
This means that some of the extreme trans-Neptunian objects we found could have actually come from the Oort Cloud, which is very cool. However, the team’s simulations also showed that the grouping of objects in the Oort cloud would be weaker than that of objects from the Kuiper Belt, closer.
This suggests that a more eccentric orbit for the New Planet would better explain the data than the orbit of the 2019 research work.
We will not know exactly how eccentric that orbit might be until more studies can be performed on the grouped objects to determine which of them came from the inner Oort cloud; but, there is a limit to how eccentric the orbit can become before it is no longer consistent with our observations of the outer solar system.
Because the hypothetical planet is so far away and so faint, our chances of observing it are really low, so this information can be used to refine the patterns and stop us from looking for it in places where we might not. either – hopefully leading to a detection of this elusive beast.
Even though we never found her, the discoveries she made were wonderful. A whole bunch of new Jovian moons and super-distant dwarf planets is nothing to sneeze at.
Batygin and Brown’s new work was accepted The Astrophysical Journal Lettersand is available on arXiv.