The Orion Nebula, Messier 42, is a H II region excited by stars in the Trapezium Cluster, the dense concentration of bright, hot stars near the center of the image. In total, the Trapezium and the associated cluster contains more than three thousand stars. The Nebula itself is a gaseous bubble formed on the front side of the Orion A Molecular Cloud. The bright, extended nebulosity seen in this image can be attributed to scattered starlight from dust in the nebula, various hydrogen emission lines, and shocked molecular hydrogen at 2 microns. To the north of the Orion Nebula is the OMC-2 molecular cloud and a series of red stars signifying young, embedded protostellar objects.
Note also the bipolar nebula in this region. Finally, at the top of the image is the H II region NGC 1977. This nebula is much brighter at optical wavelengths, although faint wisps of nebulosity are apparent in this image. The right-most object among the pair of bright blue stars is the ionizing source for NGC 1977.
The star forming regions shown in the figure are just a few of the many embedded star-forming sites in the Orion Molecular Cloud. At a distance of about 1500 to 1600 light years, this cloud represents the closest site of high mass star formation to the sun, and therefore provides a unique laboratory for studies by astronomers at many wavelengths.
This image required only 10 minutes of 2MASS observation time. Mosaic image construction by E. Kopan (IPAC). Image Field size is 0.81 x 1.19 deg.
Last Modification: September 7, 2001