Borisov, a Comet From Outer Space

On August 30, Gennady Borisov, an amateur astronomer, discovered a comet from the MARGO astronomical observatory in Nauchnyy, Crimea.

He immediately communicated the finding to the International Astronomical Union, which studied its orbit and confirmed its exosolar origin.

In this way, the comet, called 2I / Borisov in honor of its discoverer, becomes the second interstellar object detected after the discovery of Oumuamua in November 2017.

Now, a team of astronomers led by Piotr Guzik of the Jagiellonian University in Krakow, Poland, has published the characteristics of this celestial body in the latest issue of the journal  Nature Astronomy.

Researchers have used data and images from the William Herschel Telescope in La Palma and the Gemini North Telescope in Maunakea, Hawaii.

The comet is mainly composed of ice, dust and rocks, has a reddish appearance and its solid core has a radius of approximately one kilometer.

Unlike Oumuamua, which is not clear if it is an asteroid or not, with Borisov there was no doubt that it was a comet.

“We immediately noticed the coma (atmosphere surrounding the body) and the tail characteristic of comets that were not seen around Oumuamua,” says Michal Drahus, a researcher at the Polish university and one of the authors of the study.

Although Borisov was not born in the solar system, its characteristics are very similar to those of comets that were already known, in terms of color, size and composition, but differ in the type of orbit.

“The comets of the solar system move in elliptical orbits around the Sun. This implies that they are seen again periodically. However, Borisov is an interstellar comet.”

“This means that it does not come from our solar system and that  its orbit is hyperbolic.”

“Until December of this year it will be approaching the Sun, but then it will move away to never return,” explains Inés Pastor Marazuela, a researcher at the University of Amsterdam and co-author of the study.

Indeed, the closest encounter to Earth is scheduled on December 8 and may be observable until September 2020, which gives researchers time to acquire an even more complete and accurate data set.

“The visit of this comet will provide us with an excellent opportunity to know in great detail the properties of a comet formed in a different environment than the one in the solar system, and will allow us to better understand the history of formation of smaller bodies in other systems planetariums,” clarifies Pastor Marazuela.

“We can safely say that research on this body will be transformative for planetary astronomy and a milestone for astronomy in general,” concludes Guzik.



Source: Ambientum