Astronomers have published the results of the analysis of the data collected by space telescopes “Hubble” and “Swift”, as well as ground system of the radio telescopes of ALMA in the study of the first interstellar comet Borisov. The nucleus of the comet was very rich in carbon monoxide, which suggests that it is formed in the outer part of the protoplanetary disk, which was a lot of carbon. Articles (1,2) published in the journal Nature Astronomy.
Comet 2I/Borisov was discovered on 30 August 2019 Amateur astronomer Gennady Borisov. Further observations showedthat its orbit has an eccentricity of 3.36, which makes it the second known interstellar object after an asteroid 1I/Omwamwi. The study of such bodies allows you to learn about the properties and composition of planetesimals in protoplanetary disks around other stars, is no exception and the comet Borisov, which for a long time following a lot of ground and space telescopes. The comet passed perihelion on 8 December 2019 and be removed from the Sun, returning to interstellar space, and a meeting with our star has not gone unnoticed — the increased activity of the comet’s nucleus led to its destruction.
Early observations made it possible to argue that the comet Borisov is very similar for similar objects in the Solar system. Now two teams of astronomers published the results of data analysis a new, more detailed observations of the comet. The first group, headed by Martin Cordilera (Martin Cordiner) and Stephanie Milam (Stefanie Milam) investigated the comet in the millimeter range by means of a system of radio telescopes ALMA 15-16 December 2019. The second group of scientists led by Dennis Bodewits (Dennis Bodewits) worked with data from the spectrograph COS onboard the space telescope “Hubble” received in the period from 11 December 2019 13 January 2020, and with the data of ultraviolet UVOT telescope installed on Board the space Observatory “Swift”, obtained in the period 19-22 December 2019 13 January 2020.
ALMA have detected in the coma of a molecule of hydrocyanic acid (NCN) and carbon monoxide (CO), the rate of formation of which is 7×1023 , and 4.4×1026 molecules per second, respectively. Molecules of carbon disulphide (CS) and methanol (CH3OH) were not detected in the coma. The content of HCN molecules relative to the molecules of water (0,06-0,16 per cent) is similar to the values obtained for comets in the Solar system, but the content of CO molecules relative to the molecules NCN (35-105 percent) proved to be one of the greatest that ever has been reported for the comets observed within 2-2,5 astronomical units from the Sun. Data telescope “Hubble” and “Swift” also indicate a record high ratio of CO/H2O in the coma of comet Borisov on the level 130-155 per cent, of kernel in whom every second was received 30-50 kilograms of carbon monoxide. The rate of water loss from the comet’s nucleus decreased rapidly after the perihelion passage, and the rate of loss remained constant or increased during this observation period.