A fiery ribbon of gas in the constellation Orion has been imaged like never before in a new photograph released on Wednesday by the European Southern Observatory (ESO).
Orion is one of the best-known of all constellations, and is among the easiest to find. What is more difficult to find is a fiery ribbon of gas and dust that is contained within that constellation. Called the Orion Molecular Cloud, this cloud of gas glows at wavelengths too long for the human eye to see. It was imaged as part of the Atacama Pathfinder Experiment (APEX), conducted in Chile. The APEX telescope is located over 16,000 feet above sea level in the Chilean Andes. The camera they used took the photo in the sub-millimeter range of the wavelength, in the infrared part of the spectrum.
Dust clouds block much of the visible light produced by the nebula. Located 1,350 light years from Earth, the ribbon houses a stellar nursery, hatching new stars that give off energy in the form of electromagnetic radiation. That energy is then absorbed by the surrounding gas, which then releases it in the form of photons, which we observe as light. Although the "light" seen in the latest image could not be seen by the human eye, it is shown in the image as an orange glow, layered over a normal photograph of the ribbon in visible light.
The ribbon is hundreds of light-years long. To the upper-right in the photograph is the familiar Orion Nebula, M-42. This can be easily seen with the naked eye as the fuzzy middle "star" in Orion's belt. This nebula is the nearest large stellar birthplace to Earth. The gas visible in this photograph has a temperature less than 20 degrees Fahrenheit above absolute zero.
Astronomers have been searching this area of space for protostars, which are stars in their earliest stage of evolution. The scientists are using data from APEX in this endeavor, and had been using information from the Herschel Space Telescope, until the orbiting observatory ran out of coolant in April, ending its mission. The astronomers hope to be able to see a star "turn on" its nuclear furnace for the first time.
