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How big is Betelgeuse?

Betelgeuse is 1.1 billion kilometers

Introducing Betelgeuse: A Giant Among Stars

Have you ever looked up at the night sky and wondered about the stars? Each one is unique, with its own story to tell. One of the most fascinating stars is Betelgeuse, a red supergiant. Known as the tenth-brightest star in the night sky, Betelgeuse is a star that demands attention. And when we say it’s big, we mean it’s really, really big!

How Big is Betelgeuse?

When we say Betelgeuse is big, we’re not joking. Imagine our own Sun - a pretty big star, right? Now, think about a star that could swallow our Sun and still have room for Mars, Venus, Earth, and even extend beyond the asteroid belt. That’s Betelgeuse. To put it into perspective:

  • Betelgeuse’s mass is at least ten times that of our Sun and could be up to twenty times greater. - If Betelgeuse was at the center of our Solar System, its surface would stretch past Mars and into the asteroid belt. - Betelgeuse’s diameter is estimated to be over 900 times that of our Sun.

The Changing Size of Betelgeuse

One of the unique things about Betelgeuse is that it’s not always the same size. It’s a variable star, which means it pulsates, growing and shrinking over time. On average, its diameter ranges from 0.042 to 0.056 arcseconds. That’s a change in size that’s too small for us to see from Earth, but it’s a big deal in the world of astronomy.

Betelgeuse’s Place in the Universe

Betelgeuse is part of the constellation Orion, where it shines brightly as the second-brightest star. But it’s not just in Orion where Betelgeuse makes its mark. It’s also one of the brightest stars in the entire night sky. At near-infrared wavelengths, Betelgeuse is actually the brightest star we can see. Despite its brightness and size, Betelgeuse is not close to us. It’s about 500 to 600 light-years away from the Sun. That’s a huge distance - so far that the light we see from Betelgeuse today actually left the star hundreds of years ago!

A Star on the Move

Betelgeuse doesn’t stay still. It’s a runaway star, moving swiftly through the universe at a speed of 30 km/s. This movement creates a bow shock over four light-years wide. That’s a lot of space!

A Future Supernova

With its massive size and rapid evolution, Betelgeuse is expected to end its life in a spectacular way - with a supernova explosion. This event, which could happen within the next 100,000 years, will cause Betelgeuse to shine as bright as the half-Moon for over three months. Don’t worry, though. Despite the size and brightness of this event, life on Earth will be unharmed.

Conclusion

Betelgeuse is a fascinating star, from its immense size to its future as a supernova. It’s a reminder of the incredible wonders found in our universe. So, the next time you look up at the night sky, see if you can spot Betelgeuse. It’s a sight you won’t forget.

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