Last week, the Minor Planet Centre announced that astronomers had tentatively discovered the second interstellar object on record – and now we have a picture of it.
Amateur astronomer Gennady Borisov discovered the object, provisionally named Comet C/2019 Q4 (Borisov), on August 30. Follow-up observations have revealed that the object has a hyperbolic orbit, meaning that it was travelling with enough velocity to escape the solar system’s gravity – and implying that it did not originate in this solar system. It’s an exciting discovery.
“What’s exciting scientifically is we can make a comparison, how is this one different from ‘Oumuamua,” the first interstellar object, MPC director Matthew Holman told Gizmodo last week.
Astronomers operating the Gemini Multi-Object Spectrograph instrument at the Gemini North Telescope in Hawaii captured the image on the night of September 10. Astronomers scrambled to take the image, and after hearing the final details at 3:00 a.m. local time, observed the object less than two hours later, according to a press release.
If follow-up observations confirm C/2019 Q4 (Borisov)’s interstellar status, it would be the second interstellar object on record after ‘Oumuamua, which was spotted in 2017. Researchers have already started thinking about how the two objects differ. The Gemini North image shows details of a fuzzy coma and a tail, two features of comets unobserved on ‘Oumuamua.
The new object is presently quite close to the Sun – it appears low in the sky before sunrise, and the twilight makes for difficult observing conditions. Borisov thankfully caught it on its approach, and scientists will be able to further image the object on its outward journey, according to Holman. More telescopes pointing at the object will confirm whether it’s actually from out of this solar system, and reveal more about its origin.
Featured image: Gemini Observatory/NSF/AURA