[BenLurkin]

I have yet another dumb question: After all these billions of years, why is this “massive” comet just now making its first run at the sun?

[plain talk]

“it received an unexpected gravitational kick, probably from a star passing by the outer edges of the solar system.”

Interesting. I wonder what star this might be? The Oort cloud is about .79 light years from the sun. Proxima Centauri is 4.2 light years from our sun.

Here is a list of the nearest stars to our solar system.
https://en.wikipedia.org/wiki/List_of_nearest_stars_and_brown_dwarfs

[Rebelbase]

I hope this is the one that comes comes with trumpet music.

[Leep]

I heard the sun is pretty big?

[GaltAdonis]

Theoretical depiction of the Oort Cloud -

[PIF]

The massive, strange Comet K2 is touring the solar system, surprising scientists as it goes
—
Looking for a juicy target, gathering info on locals in preparation for a casual strike by a third and hidden party.

Most likely an ultra dense object launched several light years away, traveling at some part of lightspeed, aimed at the heart of the Sun, the strike causing the Sun to nova, sterilizing the inner Solar System.