Westerlund 1 facts for kids
Westerlund 1 (also called Wd1 or Ara Cluster) is a very special group of young stars. It is a "super star cluster," meaning it has many huge, bright stars packed closely together. This cluster is located in our own Milky Way galaxy. It is about 12,000 to 16,000 light years away from Earth. That's a very long distance!
Westerlund 1 is the biggest and heaviest young star cluster we know of in our local group of galaxies. A scientist named Bengt Westerlund found it in 1961. For many years, it was hard to study. This was because a lot of gas and dust blocked its light. This blocking is called "interstellar extinction." Scientists think that Westerlund 1 will likely become a globular cluster in the future.
This cluster is home to many rare and giant stars. These include six yellow hypergiants and four red supergiants. There are also 24 Wolf-Rayet stars and a luminous blue variable. Many other huge OB supergiants are also found here. One very unusual star is an sgB[e] star. It might be what's left after two stars crashed into each other.
Scientists have also found a strange X-ray pulsar in Westerlund 1. This is a neutron star that spins slowly. It formed from a very massive star. Scientists believe all the stars in Westerlund 1 formed at the same time. This means they are all about the same age. They also have similar chemical makeups.
Westerlund 1 is important for astronomers. It has some of the biggest and least understood stars in our galaxy. Because it's relatively close, it helps us learn about other "super star clusters" that are much farther away.
How Far Away Is Westerlund 1?
It is too far to measure the exact distance to Westerlund 1 directly. Scientists cannot use a method called parallax. This method measures how a star's position seems to shift as Earth moves.
Instead, astronomers guess the distance. They look at how bright the stars should be. Then they compare this to how bright they appear from Earth. This helps them estimate the "interstellar extinction" (how much light is blocked). Different methods give slightly different distances. Some say it's 5,000 parsecs away. Others say it's 3,600 parsecs away. These distances place Westerlund 1 near the edge of the Milky Way's central bar shape.
Images for kids
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Images of Westerlund 1: The left picture shows visible light. All stars look red because gas blocks their blue light. The right picture shows X-ray light. The magnetar (a type of neutron star) is marked.
See also
In Spanish: Westerlund 1 para niños
