Very big news: A comet discovered just a couple of weeks ago appears to be one the most rare and exciting of all cosmic beasts: An interstellar visitor — literally an object coming from interstellar space, from an alien star!
The object is called C/2019 Q4 (Borisov) — though that name may change, as I'll get to in a sec — and it was discovered in observations taken on August 30, 2019 at the Crimean Astrophysical Observatory by Gennady Borisov using a custom 0.65-meter telescope. It didn't take long to find the object had an, um, unusual orbit, and follow-up observations taken a few days later using a much larger telescope confirmed its strange nature. There have now been quite a few observations, and although many mysteries remain, we can be pretty sure this thing came from Out There.
To be probably too careful here, I want to say that there is a slim chance it's not from outside our solar system, but honestly at this point I wouldn’t put much money on that. As more observations come in it looks more and more like this is the real deal.
Astronomers are celebrating new images of the interstellar comet that was discovered zipping through our solar system last month.
A new image of comet C/2019 Q4, taken by the Nordic Optical Telescope and shared with Popular Mechanics, provides a new perspective on the interstellar visitor.
In the next few months, C/2019 Q4 could reveal insight into the formation of distant star systems and, possibly, the universe.
Continued observation and analysis of this object has confirmed its
hyperbolic orbit and interstellar origin. The Minor Planet Center has
therefore assigned the permanent interstellar designation 2I to it. The IAU
Working Group for Small Body Nomenclature has decided to retain the name
Borisov for the permanent designation.
An interstellar comet C/2019 Q4 was discovered on August 30 by an amateur astronomer Gennady Borisov at MARGOT observatory (Crimea). One of the obvious questions is where does this object come from. Taking an orbit obtained by Nakano and published by MPC in CBET 4670 we numerically integrated the motion of C/2019 Q4, the sun and 647 stars or stellar systems from our list of potential stellar perturbers of cometary motion. As a result we obtained that 1 Myr ago C/2019 Q4 passed double star Kruger 60 at a small distance of 1.74 pc having an extremely small relative velocity of 3.43 km/s. Almost the same results were obtained from our own orbital solutions.
On 12 October 2019, the NASA/ESA Hubble Space Telescope provided astronomers with their best look yet at an interstellar visitor – Comet 2I/Borisov – which is believed to have arrived here from another planetary system elsewhere in our galaxy.