Galaxies vigorously produce stars during starburst episodes especially after the merger of two galaxies.
All galaxies in the universe are made from billions of stars. Our Milky Way contains about 200-400 billion of them. Typically, stars continuously form from the gas present in the galactic center region as well as in the spiral arms. At least this is how it goes for quiet galaxies. But for some others, they form much of their stellar content in enormous bursts. This occurs when two galaxies fly through each other and collide. As their huge gas reservoirs merge, stars vigorously form in short succession. The turbulent new gas and dust triggers star formation, with stars forming up to 10 times faster than in quiescent galaxies. The abundance of new stars lights up the new formed galaxy and when observed, is a sign for a recent galaxy merger.
A beautiful example of a merging galaxy is the Antennae Galaxy. This newly forming system is producing billions of stars.
New stars are born at a high rate the the merging galaxy Messier 82 as part of the red structured material that is merging from the galaxy’s center region.
New stars are born at a high rate the the merging galaxy Messier 82 as part of the red structured material that is merging from the galaxy’s center region. Credit: ESA