UPDATE:  Solved by Roger at 12:15 CDT

Happy Riddle Day!  Or, as the unenlightened like to say; Happy Saturday.  I’m glad to see you back to challenge the riddle once again.

Today’s riddle will be fun (I know, I say that every Saturday) and quick.  We’re still dealing with reality, so you’ll find your answer today in textbooks.  With that in mind, let’s hop right on it:

Modern bronze copy of Young Centaur, Malmaison

We think of this as one thing, but it’s actually composed of many things.

This was known to our ancestors.

You don’t have to go outside the neighborhood to find this one.

NASA/HST Gliese 623b (large one) and 623a (smaller star at about 4:00)

While considered to be very old, parts of this are much younger…

…which is odd, when you think about it.

In fact, it may have started out as something altogether different, and then got — well — disrupted.

Some studies seem to show a hungry little monster hiding out and quietly eating everything in its path.

But later studies seem to show otherwise.

Whatever is going on, there’s a lot of it.

Portrait by Thomas Murray, ca 1687

Of it’s group, today’s answer is one of the most massive.

This was incorrectly described in Ptolemy’s catalog.

The person who “discovered” it got it wrong, too.

Uh-oh. Looks like somebody divided by zero.

There you have it; one fresh, new riddle.  I know everybody will be right on top of this one, so get your guesses in early.  You know where to find me; as always, lurking in the comment section.  Hey!  I’m getting pretty good at lurking, aren’t I?