Starburst Mysteries in Galaxy MCG+07-33-027

Galaxy MCG+07-33-027 is seen face-on in this image, and the galaxy’s spiral arms and the bright star-forming regions within them are clearly visible. The dazzling object to the right is a foreground star much closer to Earth. The galaxy lies some 300 million light-years away from us in the direction of the constellation Hercules and is currently experiencing an extraordinarily high rate of star formation — a starburst. Normal galaxies produce only a couple of new stars per year, but starburst galaxies like MCG+07-33-027 can produce a hundred times more. In order to form stars, a parent galaxy has to hold a large reservoir of gas, which is slowly depleted to spawn stars over time. For galaxies in a state of starburst, this intense period of star formation has to be triggered somehow, often due to a collision with another galaxy. MCG+07-33-027, however, appears different; while many galaxies are located within a large cluster of galaxies, MCG+07-33-027 is rather isolated. Thus, the triggering of the starburst was most likely not due to a collision with a neighboring or passing galaxy. Astronomers are still speculating about the cause.