Two weeks ago, a Crimean astronomer discovered C/2019 Q4, a high-speed space object that is likely to be the first interstellar comet and second interstellar object ever discovered. The body is getting closer and closer to the inner Solar System and is getting brighter, allowing for more observations.
Astronomers at the Gemini Observatory have now delivered the first multicolored photograph of the object. The image was taken during the night between September 9 and 10 using the Gemini Multi-Object Spectrograph on the Gemini North Telescope on Hawaii’s Maunakea.
The image was taken with two filters with four 60-second exposures which show perfectly its fuzzy appearance, bright core, and tail. These are all hallmarks of a comet. The tail suggests the comet is outgassing (releasing gas), something not seen at all from ‘Oumuamua, the first confirmed interstellar object, which passed through the inner Solar System two years ago.
“This image was possible because of Gemini’s ability to rapidly adjust observations and observe objects like this, which have very short windows of visibility,” Andrew Stephens of the Gemini Observatory, who coordinated the observations, said in a statement. “However, we really had to scramble for this one since we got the final details at 3:00 am and were observing it by 4:45!”
C/2019 Q4 is yet to be confirmed to be an interstellar object but its orbit and speed strongly suggest it is. The comet is over 400 million kilometers (250 million miles) from the Sun and its current velocity is about 150,000 kilometers (93,000 miles) per hour, much faster than any known Solar System object at that distance.
NASA reported that the comet's nucleus is estimated to be between 2 and 16 kilometers (1.2-10 miles) across. The comet is coming in at a 40-degree angle with respect to the orbital plane of the Solar System, which it will cross on October 26. The closest it will get to the Sun is twice as far as the Earth on December 8, when it will be roughly 300 million kilometers (190 million miles) away.
Researchers believe that at any given time there is at least one interstellar object within the orbit of Mars, though we will never see all of them as the vast majority are too small and faint to be spotted.
C/2019 Q4 was first observed on August 30 by Gennady Borisov at the MARGO observatory in Nauchnij, Crimea.