A new photo of interstellar comet 2I/Borisov taken using a spectrometer at the Keck Observatory in Hawaii is now the best obtained so far and can offer new information on this object that is going through the solar system. Astronomers Pieter van Dokkum, Cheng-Han Hsieh, Shany Danieli and Gregory Laughlin of Yale University captured this image on November 24 and it includes the comet’s tail, shown in its length of nearly 160,000 kilometers in a composition that puts together 2I/Borisov and the Earth.
Comet 2I/Borisov, initially designated as C/2019 Q4, was discovered on August 30, 2019 by the amateur astronomer Gennady Borisov and after some observations the data about its orbit started suggesting its interstellar origin. confirmed by follow-up observations.
The activity of interstellar comet 2I/Borisov will continue to increase for a while, until its closest approach to the Sun, estimated for December 8, 2019. Even at that point, its distance from the Sun will still be almost 300 million kilometers, enough to make it active. Already in recent weeks various molecules were detected in its coma and now its tail has an estimated length at about 14 times the Earth’s diameter even if its nucleus seems small, with an estimated length of just over 1.5 kilometers.
The LRIS (Low Resolution Imaging Spectrometer) instrument mounted on the 10-meter telescope at the Keck Observatory is one of many used to study interstellar comet 2I/Borisov after its discovery. Professor Pieter van Dokkum explained that interstellar objects such as these are a gold mine of data regarding solar systems other than ours. We can study gas and materials surrounding the comet to understand its chemical make-up and compare it with that of other comets in our solar system.
The photo (Courtesy Pieter van Dokkum, Cheng-Han Hsieh, Shany Danieli, Gregory Laughlin. All rights reserved) taken shows interstellar comet 2I/Borisov with all its tail. To appreciate that tail’s length, the astronomers created a composition that shows the Earth next to 2I/Borisov. Studies will continue by many astronomers in the coming months, even after the comet moves away from the Sun towards interstellar space, to try to discover its secrets.