Herschel's view of the Orion B molecular cloud - annotated
This image shows the Orion B molecular cloud, a vast star-forming complex in the constellation Orion, as viewed at far-infrared wavelengths with ESA's Herschel Space Observatory. At about 1300 light-years, Orion B is one of the closest regions of star formation.
This massive stellar nursery reveals itself through the glow of cosmic dust in the interstellar material that pervades it. Heated by radiation from newborn stars, the dust shines brightly at far-infrared wavelengths, revealing a tangled network of filaments.
The bright yellow, white and pink areas in the image are the densest regions, where many protostars and newborn stars are found. Darker regions correspond to colder portions of the cloud where star formation is not as active. On the right-hand side of the image, the cloud exhibits a very sharp edge where the material in Orion B is being compressed by powerful winds blowing from clusters of massive stars located beyond the field of this image. These mighty stellar winds have sculpted the iconic Horsehead Nebula, glowing brightly on the right-hand edge of the Herschel image.
Herschel's far-infrared view of Orion B also shows other pockets of star-forming gas and dust nestled in the intricate structure of this cloud: NGC 2024, also known as the Flame Nebula, and NGC 2023 on the right-hand side of the image, to the left of the Horsehead Nebula; and NGC 2071 and NGC 2068 on the left-hand side of the image.
This false-colour image combines data acquired with the PACS instrument at 70 micron (shown in blue) and 160 micron (shown in green) and with the SPIRE instrument at 250 micron (shown in red).