The interstellar comet Borisov is very different from the objects present in our solar system. Two studies of filtering light through a dust and gas cover revealed its incredible purity.

An intergovernmental visitor of eternal purity

Seen in august 2019, Borisov A trajectory indicated that it came from another star. While asteroids OumuamuaThe first interstellar object to be discovered was identified as a solar system, leaving astronomers with little time to study it, this second visitor first detected can be seen in detail.

With reference to the work published in the magazine Nature astronomy, Bin yang | And his colleaguesEuropean Southern Observatory we usedAtacama Large Millimeter / Submillimeter Array (ALMA) And this Very Large Telescope (VLT) To examine the properties of comet dust and found that it emits about 200 kg of dust per second. It was also revealed that Borisov The typical solar system contained much more carbon monoxide than comets, but it was not evenly distributed.

« This comet is like a group of small, fluffy snowballs made in very different places. “, Please explain That. « The varying amounts of carbon monoxide indicate that Borisov began to form closer to his original star before exiting the system, probably under the influence of the giant planets that formed it.. »

“Its light was much more polarized than that previously reflected by any other comet”

Stefano Bagnulo, ‘Armagh Observatory On United Kingdom, And his team used VLT To study the light reflected by the hair of Borisov. Featured in the magazine Nature communication, Their analysis revealed that the comet was very different from the objects in our solar system, with the exception of the comet Hale-Bopp, Perhaps a relic of his beginning.

« His light was much more polarized than previously reflected by any other comet, and his hair was remarkably smooth. “, Cast light on Baganulo. « Interaction with a star produces a jet [de matière] And a structure at the level of the hair that we do not find in Borisov. Comet is pure – it has never made contact with other stars. »

According to the researchers, this purity makes the most of the differences. Borisov And comets of the solar system, while similar to Hale-Bopp Suggest that their original star system and ours (in the early stages) were probably very close.

Better understand the diversity of our solar system and its neighborhood

According to YoungStudy of such objects is necessary to understand the diversity of other star systems. ” Comets and asteroids around other stars are so far away that it is impossible to study them individually “, He believes.” This interstellar object is a very demanding link between our solar system and other star systems.. »

And Borisov Today is too far for astronomers to continue studying, a new generation of telescopes should identify many interstellar objects in the coming years, and teach us more about our solar system and its neighborhood.