Makin’ New Starzzzzz
That’s how we say that star birth is found everywhere in the universe, in “leetspeak.” In geekspeak, we say that this picture is an excellent example of starburst regions in a galaxy that lies 12.5 million light-years away. Hubble Space Telescope imaged galaxy NGC 4449 with the Advanced Camera for Surveys, in blue, visible, infrared and H-alpha light.
Starbirth is one of the great recycling mechanisms of the cosmos. It takes material just lying around in interstellar space (in just about any galaxy) and turns it into stars. It’s a process that’s been going on for nearly as long as there’s been stuff in interstellar space to use (more than 13 billion years, for those of you keeping score at home). It’s a complicated process because a cloud of stuff just hanging there in space isn’t likely to wake up one day and say “Gee, I think I’ll become a star.” Something actually has to happen to make the cloud particles (gases and some dust) start to clump up and whirl around in a crazy birth process. It needs a push of some kind to start those materials clumping together. Maybe like a gravitational heave-ho from a passing star (that’s an old favorite). Or, even better, a nearby massive star goes supernova and the outburst shoves the gas cloud molecules and dust grains together. If there’s enough stuff to push together and enough of a push, the process gets started.
For NGC 4449, the process was likely started by a merger with another galaxy. When galaxies mingle, their clouds of gas and dust can get compressed, and that can start up the starbirth nursery. If the mingling is widespread, you get pictures like this one: a galaxy ablaze with starbirth regions. No matter how you say it, that makes for some pretty spectacular images. Read more about it here.
