The galaxy guest is exceptionally “new”

Armac / Santiago de Chile. On August 30, 2019 Amateur astronomer Gennady Borisov discovered a new comet in the Crimea, Which soon proved to be extraordinary: it came from a galaxy: a comet ejected from its own solar system millions of years ago. However, to the astonishment of astronomers, it does not appear to be different from the known comets in our solar system.

However, new observations by an international team with the European Southern Laboratory (ESO) ‘s largest telescope now show that Borisov is in a much more beautiful state than all known comets in our solar system.

The comet is “new” and has not changed

Stefano Pacnolo and his colleagues from Armor Laboratory in Great Britain report in the magazine “Nature Communications“By polarization measurements of light reflected from a comet’s gas and dust envelope – coma.” Polarity is stronger than usual for comets in our solar system, scientists say.

From this, astronomers can draw conclusions about the nature of the dust particles in a cometary coma. According to Pacnolo and colleagues the strong polarity shows that the dust particles are small and fluffy, i.e. loosely structured. From this the researchers conclude that Borisov is unusually “new” and has not changed due to external influences since its creation.

Borisov may be more original than Hale-Pop

The only known comet with similarly strong polarity is Hale-Pop. This is the most original comet, which only passed through the inner solar system for the second time in 1997 and revealed the influence of solar radiation. But while the polarity at Hale-Pope was inconsistent, in Boriso it was more or less the same as the whole coma.

“This suggests that it is more original than Borisov Hale-Pop,” said Baknulo and his colleagues. The galaxy observer never came close to the central star in its orbit. Another known galaxy in the Solar System is the asteroid Is Omwamua, discovered in 2017.

The teams studied different components

Observations of the Second International team with the radio telescope system ALMA (Atacama Large Millimeter / Submillimeter Array) in the northern Chilean Andes allow for further conclusions about the history of Boriso’s origins. Bin Yang and his colleagues at the ESO Institute in Santiago, Chile, reported in the journal Nature Astronomy that alma measurements refer to large numbers of solid rock particles larger than one millimeter in size in a coma.

It is easy to explain what initially seemed to contradict the observations made by Pacnolo and his team, Yang says: “Optical observations are sensitive to small particles in the micrometer range or below.

Borisov must have appeared in the housing system

Yang and his colleagues conclude from their observations that the comet Borisov, which already had many large rock bodies, must have formed in a part of its housing system. According to the researchers, the small rock particles identified by the alma could have come only through multiple collisions of such rocks.