The Orion complex in the constellation of the same name is home to the molecular clouds closest to the sun at a distance of 1300 to 1600 light years. These frigid clouds of molecular gases are a highly active stellar and planetary nursery. The famous region of the sky has been studied with cameras and telescopes in many different wavelength ranges.
This radio image was obtained using the SuperCam, an instrument installed in 2014 at the European Southern Observatory’s (ESO) APEX telescope in Chile. To try out the new device, a team led by Thomas Stanke from ESO recorded and has now published data from this region of the sky. They are part of a project to observe radio emissions emitted by carbon monoxide in the Orion molecular cloud complex.
The left part of the figure shows the Flame Nebula with a group of young stars in the center, which emit high-energy radiation and cause the surrounding gases to glow. The bright spot on the right marks the reflection nebula NGC 2023, to the right of which the well-known Horsehead Nebula stands out in red against the blue-black sky. The Flame Nebula and its surroundings are moving away from our solar system, with the red areas moving away from us faster than the foreground yellow ones.
The coloring, which looks like hot flames, has nothing to do with the temperature: the gas clouds are only a few dozen degrees Celsius above absolute zero. The darker background image was captured by ESO’s VISTA telescope in the infrared. The advantage of radio waves and infrared radiation over visible light is that the much longer waves penetrate even thick clouds of interstellar dust, revealing stars and other objects that would otherwise remain hidden.
“As astronomers like to say, whenever there’s a new telescope or instrument, watch Orion. There is always something new and interesting to discover,” explains Stanke. He was not disappointed: in addition to observing well-known spectacular objects, the research group discovered a new, small and almost round nebula, which they named the Cow Nebula (not visible in the picture).