Barnard's galaxy facts for kids
Barnard's Galaxy is a fascinating space object! It's a type of galaxy called an irregular barred spiral galaxy. You might also hear it called NGC 6822, IC 4895, or Caldwell 57. This galaxy is super far away, about 1.6 million light-years from us. You can find it in the night sky in the constellation of Sagittarius.
Barnard's Galaxy is part of a group of galaxies called the Local Group. Our own Milky Way galaxy is also in this group! A scientist named E.E. Barnard first discovered this galaxy way back in 1884. He used a special kind of telescope called a refractor telescope to spot it.
What Makes Barnard's Galaxy Special?
Barnard's Galaxy is one of the closest galaxies to our Milky Way. It's pretty similar in shape and what it's made of to the Small Magellanic Cloud, which is another galaxy close to us. Barnard's Galaxy is about 7,000 light-years wide. That's a huge distance!
How We Measure Distances in Space
Barnard's Galaxy is famous because it helped scientists figure out how far away galaxies are. A special type of star called a cepheid variable star was used for this. These stars get brighter and dimmer in a regular pattern. The time it takes for them to change brightness tells us how bright they truly are. By comparing their true brightness to how bright they look from Earth, scientists can calculate their distance.
In the 1920s, a famous astronomer named Edwin Hubble found 11 cepheid variable stars in Barnard's Galaxy. He used them to figure out the exact distance to the galaxy. This discovery was a really big deal!
Solving a Cosmic Mystery
Before Hubble's discovery, scientists weren't sure if "spiral nebulae" (which is what they called spiral-shaped objects in space) were part of our Milky Way or if they were separate galaxies far away. Hubble's work on Barnard's Galaxy proved that these "spiral nebulae" were actually other spiral galaxies. They are incredibly far outside our own Milky Way. This helped us understand just how big the universe truly is!
