US, WASHINGTON (ORDO NEWS) — Astronomers seem to have discovered a satellite in a large celestial body, located far beyond the orbit of Neptune.
The achievement is described in a scientific article accepted in the journal Astronomy & Astrophysics and available as a preprint .
It is very difficult to study trans-Neptune objects (TNOs): they are too far from the Sun, and therefore reflect very little light. Meanwhile, it is believed that these very bodies have least changed since the birth of the solar system.
Therefore, astronomers are happy with any information about these relics, which allows us to look into the distant past of our space family.
Trans-Neptune object (84522) 2002 TC 302 was discovered in 2002. Until 2018, it was observed at least 126 times. Scientists have calculated that it revolves around the sun for 417 earth years. Using the infrared telescopes Herschel and Spitzer, the heat flux from this celestial body was measured. According to these data, its size is calculated: about 584 kilometers.
Probably, such a large object took a spherical shape under the influence of its own gravity. If so, then (84522) 2002 TC 302 should be reckoned among the dwarf planets, which so far are only five in the solar system . This further fuels interest in him.
In 2018, the “foundling” gave astronomers a gift: he covered himself with a star. It would seem nothing special. But in fact, a block with a diameter of hundreds of kilometers at such a distance looks like a small dot in the sky. Very rarely does it “meet” so accurately with any luminary accessible to the earth’s telescopes to close it with itself.
Scientists did not miss the moment. Instruments from Italy, Spain, France, Slovenia and Switzerland aimed at the right area of the sky. Instruments accurately measured whether an eclipse of a star was observed from this point of the globe, and if so, when did it begin and when did it end.
These data made it possible to calculate the diameter of the object regardless of the data of Herschel and Spitzer.
Of the 14 instruments, 12 entered the shadow region (84522) of 2002 TC 302 and recorded eclipses. By the way, before this, not a single eclipse of a star by any TNO, except Pluto, was observed simultaneously from so many points.
According to these data, astronomers re-determined the size of the celestial body. And it turned out to be approximately 500 kilometers, which is 84 kilometers less than infrared data.
What does this mean? Probably nothing. The measurements of “Herschel” and “Spitzer” had such an error that the new figures fit into it completely. But there is a more intriguing interpretation.
Experts estimate that (84522) 2002 TC 302 could have a moon with a diameter of about 200 kilometers, located 2,000 kilometers from it. She could fall into the frame of infrared telescopes.
For these instruments, she merges with her cartridge, increasing its estimated diameter. Even Hubble, which at one time also observed (84522) 2002 TC 302 , could not distinguish between these two separate objects .
But during the eclipse of the star on January 28, 2018, the moon could be behind the studied TNO, that is, from the opposite side to the Earth. The “master” obscured his companion, and he did not increase his size in the eyes of astronomers.
Of course, this is not the first satellite found at a trans-Neptune object, even if you do not take into account the moon of Pluto. But each such find is very valuable to astronomers. After all, the size and orbit of the moon allow us to understand where it could come from. And this is already important information on how celestial bodies are formed.
Recall that the strange form of the trans-Neptune object Arrokot has already helped specialists make a choice between the two models of planet formation (or at least provided strong evidence in favor of one of them). Researchers hope to get the same information from TNOs with satellites.
However, it is not yet known whether (84522) 2002 TC 302 really has a moon. Only further observations will help answer this question.
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