Starry Bug
by CritterKeeper on Feb.03, 2010, under Bugs, birds and other animals
Credit: NASA & ESA
Floating like a bug under a microscope, I Zwicky 18 is an odd-looking galaxy. Astronomers previously thought this peculiar galaxy was very young because it resembles galaxies typically found in the early universe. But images from NASA’s Hubble Space Telescope show older stars within the galaxy leading scientists to update their ideas. They now believe I Zwicky 18 was born about the same time as the Milky Way Galaxy and the Andromeda Galaxy.
Explore the image of this dwarf irregular galaxy. It is much smaller than the Milky Way and has more in common with the Magellanic Clouds. Look for the knots of blue-white stars. New stars are forming at furious rates within these starburst regions. Bubbles of wispy blue gas surround the starburst areas. Supernovae and strong solar winds from the new stars blow away gas and dust forming these wispy bubbles. Intense ultraviolet radiation causes the whole star cloud to glow. In addition to the new, blue-white stars, look for reddish stars in I Zwicky 18 and the companion galaxy nearby. These reddish stars are more than 10 billion years old; more than twice the age of our own Sun. The companion galaxy may be tugging on I Zwicky 18 and causing the recent star formation.
Farther away in this image, you can see ancient fully-formed elliptical galaxies as well as edge-on and face-on spiral galaxies. I Zwicky 18 is about 60 million light-years from Earth toward the constellation of Ursa Major the Great Bear.
:dwarf galaxy, Hubble Space Telescope, I Zw 18, I Zwicky 18, irregular galaxy, Magellanic Clouds, NASA, Starburst Galaxy

Zoom in and out and pan around the images to find your own patterns in the stars. Be creative and think outside the box.