Swan Nebula

NASA's Stratospheric Observatory for Infrared Astronomy (SOFIA) detected the blue areas (20 microns) near the center of this composite image of the Swan Nebula, revealing gas as it’s heated by massive stars located at the center. The green areas (37 microns) trace dust as it’s warmed both by massive stars and nearby newborn stars. The red areas near the edge represent cold dust that was detected by the Herschel Space Telescope (70 microns), while the white star field was detected by the Spitzer Space Telescope (3.6 microns).