The colorful image shows multiple star clusters. All were created from the same dense gas and dust clumps, but not all of the star clusters are the same age. Essentially, the image shows generations of star clusters, from young to older and more evolved.
The swath of green and orange that fills the left portion of the image is a gas and dust cloud called a nebula. The red glow to the right is dust heated by the stars’ radiation.
The red, white and green bright point towards the right really combines four differently colored wavelengths of infrared, which we can’t see.
The dark slash in the middle of the green delta on the left is full of baby stars, represented as red and yellow dots. This is called Cepheus C, a stellar nursery where stars are born. One day, it will look like the brighter part of the image as the stars age and the wind they create blows away the gas and dust.
In the top right side of the image, there’s a second large nebula with another star cluster, known as Cepheus B. The dark spot full of red and blue stars is between 4 and 5 million years old. Cepheus C will look like this in the future.
On the bottom right, there’s a blue star with a red slash of light around it. Astronomers call this a “runaway star,” and the red slash is a shock wave as it zips through the surrounding gas and dust.
These are found in the constellation Cepheus, which is near Cassiopeia.
The Spitzer Space Telescope is in NASA’s Great Observatories family. Spitzer detects infrared light, while Hubble captures visible and UV light, Compton was designed for gamma rays and Chandra sees X-rays.