Comet C/2019 Q4 (Borisov)
December 1 @ 03:00 - December 10 @ 05:00
Comet Borisov is clearly an interstellar comet from outside the solar system with a speed of 33 km/s which will increase to 44 km/s with a gravitational assist from our Sun. At these speeds it is in a hyperbolic orbit
The comet will make its closest approach to the sun on December 7,and will come closest to Earth, within 180 million miles, on December 29. It has a velocity of 93,000 mph (150,000 kph) which exceeds any comet speed originating from the Oort cloud or anywhere in our Sun’s vicinity and will exit the solar system.
It is expected to get to peak brightness in mid December and remain observable in a moderate sized scope at magnitude 14.7 until April 2020. (We’ll see about that)
It will be at its best from Dec 1st through the 10th (perihelion) before the full Moon on Dec 12. It will be an early morning event.
For Comet Borisov ephemeris visit the Minor Planet Center
You can follow it on Sky & Telescope‘s web site.