Vega

When it comes to understanding a star, it’s all a matter of perspective. The angle at which you view the star makes a big difference in what you know about it.

Consider Vega, the leading light of the constellation Lyra and one of the brighter stars in the northern sky. It’s in the northeast at nightfall, and climbs high overhead later on.

For a long time, astronomers thought Vega was about three times as massive as the Sun, and no more than a hundred million years old. So when they discovered a cloud of dust grains around Vega, they thought it might be raw material for planets.

But it turns out they were seeing Vega from a different angle than thought. We’re looking almost directly down on one of the star’s poles. That perspective makes it more difficult to measure Vega’s details.

Once they knew the correct angle, astronomers determined that the star spins so fast that it’s almost ripping itself apart. They also found that Vega’s a bit smaller than thought, and hundreds of millions of years older.

Today, perhaps the best estimate puts Vega’s age at about 455 million years. That’s too old for the dust around Vega to be making new planets. In fact, Vega appears to already have at least one planet — a giant that’s much bigger than Earth, and much closer to its star. So the dust probably is debris from collisions between asteroids or other bodies — maybe even fully grown planets.

Script by Damond Benningfield