♪ NARRATOR: Now, while a lot of smaller black holes enjoy spending time by themselves,
others can be a bit more ... social!
To be specific, black holes often love to dance with other objects in the universe.
Sometimes, the dance begins with two stars, long before the black hole is even part of the picture.
Then, one day, one of the two stars goes supernova, and …
pop! The dance continues, but with a new partner.
Other times, when another massive object – like a star –
happens to pass by a black hole, it, and the black hole, can't help but dance together!
In either case, the black hole could even pull stuff off of its new friend to make a fancy accretion disk.
Look at it go!
And while these first two black holes have been paired up with stars,
there are a quite a few other potential dance partners out there in the universe.
Smaller black holes have a great time dancing with low-mass stars, high-mass stars, white dwarfs, neutron stars,
unicorns … wait, what?
[record scratch, music stops]
NARRATOR: Off you go, then! Shoo!
[unicorn whinnies and flies off]
NARRATOR: Ahem. Anyway, they can also dance with other black holes, including really, really big ones.
And sometimes, when they're dancing with a giant star, that giant star can go supernova,
eventually producing another neutron star, or ... voila! A second black hole!
And, if either of those two get a bit too close to the other black hole ...
You could get a new, larger, single black hole!
By the way, did you hear that? When two black holes collide, they also produce a ton of energy as ripples in space-time,
and, if we have the right tools, we can actually listen to them! Amazing.
Well, there you have it! Now grab your telescopes, get out there, and dance the night away!
♪
[silence]