This Spitzer Space Telescope image reveals an infrared view of the Trifid Nebula - a famous, giant star-forming cloud of gas and dust located 5,400 light-years away in the constellation Sagittarius.
The false-color Spitzer image reveal a different side of the Trifid Nebula. Where dark lanes of dust are visible trisecting the nebula in visible-light images, bright regions of star-forming activity are seen in the Spitzer pictures. All together, Spitzer uncovered 30 massive embryonic stars and 120 smaller newborn stars throughout the Trifid Nebula, in both its dark lanes and luminous clouds. These stars are visible in the Spitzer image, mainly as yellow or red spots. Embryonic stars are developing stars about to burst into existence. Ten of the 30 massive embryos discovered by Spitzer were found in four dark cores, or stellar "incubators," where stars are born. Astronomers using data from the Institute of Radioastronomy millimeter telescope in Spain had previously identified these cores but thought they were not quite ripe for stars. Spitzer's highly sensitive infrared eyes were able to penetrate all four cores to reveal rapidly growing embryos.
The embryos are thought to have been triggered by a massive "type O" star, which can be seen as a white spot at the center of the nebula in all four images. Type O stars are the most massive stars, ending their brief lives in explosive supernovas. The small newborn stars probably arose at the same time as the O star, and from the same original cloud of gas and dust.
This Spitzer mosaic image combines IRAC and MIPS data, showing light of 4.5 microns (blue), 8.0 microns (green) and 24 microns (red).