In most spiral galaxies, the nucleus contains the most stars, making it brighter in visible and infrared light, but stars that are currently forming are generally found in the spiral arms. For this reason, spiral galaxies tend to have little radio light emanating from their centers. Not so with Maffei 2. Its strong radio emission indicates the presence of a starburst in its nucleus. About the same number of stars are forming in Maffei 2ΓÇÖs inner 1,500 light years as in the entire 100,000 light year expanse of the Milky Way.
Astronomers are not sure why some galaxies have starbursts and others do not. The cause may be gravitational interactions between galaxies that are passing near one another. Unfortunately, astrono-