Here is a tale ’bout a bright star named Vega.
For years, astronomers have combed through their data
and discovered that Vega is more than a star.
It’s surrounded by dust clouds: one near and one far.
Next to the star is some dust that’s quite hot.
We’ve only just found it. There isn’t a lot.
Farther away, there’s some dust that’s much colder
It comes from collisions between big icy boulders.
The hot dust’s a mystery; it shouldn’t be here.
Every speck of that dust should be gone in a year.
So Vega must have a constant supply
of fresh dust that’s brought in from somewhere on high
and thrown down real close to the star to get fried.
We talked quite a lot, Amy Bonsor and I.
Could a system of planets lie in Vega’s sky?
A system of planets on orbits between
the cold and hot dust and remain sight-unseen?
The planets could orbit right there in the middle,
toss comets from the freezer down onto the griddle.
This means the hot dust must come from the cold.
And make Vega’s warm dust in our very own mold.
Zodiacal dust is found close to the Earth.
But it comes from comets which, at their birth
condensed in the cold, way out far from the Sun.
Then were brought in by planets, kicked in by each one.
For this to work Vega’s planets must shift
They can’t empty out all the comets too quick.
And the outermost planets can’t be too big
or they’ll clean house and shut down the whole gig.
The planets serve as a conveyor belt.
Comets are delivered inward to melt.
But a gas giant planet far out in the chain
would break down the belt and the hot dust will wane.
So that is the story. We think that Vega
has a system of planets. We hope that new data
will find these planets within a few years.
For the gory details please lend me your ear,
Or rather your eyes. The paper’s right here.