Right now, the Milky Way hosts about 100 billion stars and each year that number grows. The growth rate of new stars, however, is a sluggish crawl compared to what it was a few billion years ago, explained Dominik Riechers at this year’s American Association for the Advancement of Science annual meeting in Chicago, Illinois. Riechers is an assistant professor of astronomy at Cornell University who studies galaxies and how they form and change over time. Galaxies are stellar factories, manufacturing new stars each year. Astrophysicists describe a galaxy’s star formation rate by the total mass of new stars it produces annually. Today, the Milky Way creates between one and two times the mass of our sun in the form of stars each year. But this was not always the case. NASA's Spitzer Space Telescope took this infrared image of the Sunflower galaxy. The dusty, red patches mark spots of star formation within the galaxy. Credit: NASA Jet Propulsion Laboratory If you add the mas
