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How big is Altair?

Altair is 2,800,000 kilometers

A Glance at Altair: A Bright Beacon in the Night Sky

Have you ever looked up at the night sky and wondered about the stars that you see? One of those twinkling lights is Altair, the brightest star in the Aquila constellation and twelfth-brightest star in the night sky. Altair, also known as Alpha Aquilae, is a fascinating star that stands out from the rest due to its size and unique features.

How Big is Altair?

To truly appreciate the size of Altair, it helps to compare it to something we’re familiar with. Imagine, for instance, our own Sun. Altair is about 1.8 times the size of the Sun. That means if the Sun was the size of an average soccer ball, Altair would be almost twice as big, roughly the size of a beach ball. Altair is not just bigger than the Sun, but it also spins a lot faster. This rapid rotation causes it to bulge at the equator, making it look more like an M&M shape than a perfect sphere.

The Fast-Spinning Star

Altair’s size is not its only noteworthy feature. This star rotates at a high speed of approximately 286 kilometers per second. To give you a comparison, our Sun rotates at a speed of just over 2 kilometers per second at its equator. That means Altair is spinning over 140 times faster than the Sun! This fast rotation makes Altair a very interesting star to astronomers. It has led scientists to discover that Altair is not a perfect sphere like most stars, but is actually flattened at the poles due to this high rotation speed.

Altair’s Place in the Universe

Altair is located in what astronomers call the G-cloud, which is an interstellar cloud made up of gas and dust. It’s not far from us either, at least in astronomical terms. Altair is only 16.7 light-years away from Earth. To put that into perspective, if a light-year were a mile, Altair would be about as far away as a road trip from New York to Los Angeles and back… three times!

Interesting Facts About Altair

  • Altair is one of the vertices of the Summer Triangle, a notable asterism that is easily visible during the summer months. The other two vertices are marked by the stars Deneb and Vega. - It’s an A-type main-sequence star. This means it’s in the prime of its life, burning hydrogen into helium in its core. - Altair’s apparent visual magnitude, or how bright it appears from Earth, is 0.77, making it one of the brightest stars in our night sky. In the grand scheme of things, Altair is just one of the billions of stars in our galaxy. However, its impressive size, fast rotation speed, and brightness make it a standout star that continues to capture our fascination and curiosity. So the next time you look up at the night sky, see if you can spot Altair, and remember just how unique and interesting this star truly is!
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