emission. The blue spots probably come from small clouds of gas and dust encircling the hot stars. After absorbing the stars’ radiation, these clouds heat and then reemit it as cooler infrared. 
    The large yellow and red fringed areas are probably stellar nurseries. Current theory argues that most stars in our galaxy form inside relatively dense, cold molecular nebulae—clouds of gas and dust cool enough for matter to exist inside them as molecules rather than as individual atoms. Particularly dense regions of these clouds condense and form new stars. Although such nebulae block most of the visible light emitted by new stars, the stars heat the clouds, which emit the infrared radiation seen here.