Young stars in Serpens
Here the Spitzer Space Telescope reveals the Serpens South star cluster, in which 50 or so young stars exist. They are seen as the “green, yellow, and orange-tinted specks sitting atop the black dust lane.” A supernova or galaxy collision can cause a star to form when huge clouds of hydrogen and helium collapse under mutual gravity. As the cloud collapses, it heats up and starts to spin. Since protostars are covered in dust, they can be seen only through infrared telescopes like Hubble and Spitzer. As Universe Today writes, “After about 100,000 years or so, the protostar stops growing and the disk of material surrounding it is destroyed by radiation.” Then this star, now called a T Tauri or pre-main sequence star, is visible from Earth.