Astronomers report that they have discovered a new trans-Neptunian object called 2017 OF201. It has a diameter of about 700 kilometers. If this is really true, it is a dwarf planet in an extremely elongated orbit.
New trans-Neptunian object
Astronomers have discovered a new large object beyond Neptune’s orbit. According to a paper published in the journal Earth and Planetary Astrophysics, it could be as large as 700 kilometers in diameter, so it could be a new dwarf planet.
In general, beyond the orbit of the eighth major planet in the Solar System is a huge cluster of relatively small objects, which together are commonly referred to as the Kuiper belt. Pluto, with a diameter of 2377 km, and Eris, with a diameter of 2326 km, are the largest of them, and at the same time, they noticeably do not reach in size even to the Moon.
In addition to them, there are dozens of other objects in the orbit of Neptune, with a diameter of several hundred kilometers. They have intersecting orbits and at least some of them have near-spherical shapes and their own moons. In other words, they combine the attributes of planets and non-planets.
In order to somehow deal with all this madness, once a class of dwarf planets was invented, into which Pluto was transferred. One of its attributes is its ability to acquire a spherical shape under the action of gravitational forces. However, at what minimum diameter this occurs is still a matter of debate.
Size of the new object
In general, there are dozens of potential dwarf planet candidates beyond Neptune’s orbit. However, scientists cannot accurately call them dwarf planets. It’s not just a matter of not understanding how spherical they actually are. Even whether their sizing is correct remains in question.
After all, in a telescope they are observed as tiny spots. And in order to move from brilliance to diameter, it is necessary to know their albedo, which depends on the composition, and it remains unknown in the vast majority of cases.
The object 2017 OF201 is very similar in this respect, the authors of the paper say it is larger by at least 500 km, perhaps it is even 700 km in diameter, but what is actually wrong with it no one knows.
Orbit of the object
But the orbit of the 2017 OF201 object is really interesting. As of now, when it was discovered, it is a few dozen astronomical units away from the Sun. It passed perihelion back in 1930, which means that actually now this dwarf planet is moving away from our luminary.
Its aphelion is 1600 a.u. from the Sun, which makes 2017 OF201 the dwarf planet with the largest known parameter. And this has one interesting consequence. Modern astronomical instruments can only see it at 1% of its orbit near perihelion. That is, we’re very lucky that the dwarf planet has relatively recently passed it.
This brings up another interesting thought. It is quite possible that there are many more dwarf planets in the Kuiper belt than just a few dozen. But the vast majority of them spin in very elongated orbits and are now in their distant parts. In that case, it is possible that we still don’t know about most of the relatively large objects in our own system.
According to phys.org
