A new image of the Flame Nebula shows the interstellar cloud we have never seen before.
A team of astronomers using the Atacama Pathfinder Experiment (APEX) telescope has captured the star-forming region in radio wavelengths and revealed details we had never seen before.
The Flame Nebula, located close to the famous Horsehead Nebula, is part of the Orion Molecular Cloud Complex, located in the constellation Orion, which is one of the most well-studied and imaged areas in the night sky.
"As astronomers like to say, when there is a new telescope or instrument around, Orion observes: there will always be something new and interesting to discover!" says astronomer Thomas Stanke of the European Southern Observatory.
Above: Composite image showing radio and infrared wavelengths.
The Orion complex is a large series of star-forming nebulae that span hundreds of light-years in all directions, starting at about 1,000 light-years from the solar system. Because it is so close (cosmically speaking) and so huge, it is an excellent laboratory for studying how stars are born.
The Flame Nebula is one of the many stars' kindergartens in the complex. This is what is classified as an emission fog; that is, it emits its own light, in contrast to reflection nebulae, which shine only with reflected starlight, and dark nebulae, which do not shine at all, but cast shadows across the sky like gorges in the cosmos.
What makes an emission nebula shine is the ionization of gases in the nebula by light radiation from a nearby hot star. Since young stars are often very hot, the stars' kindergartens tend to shine brightly. The Flame Nebula is home to a cluster of hundreds of newly formed stars, concentrated in its center.
But stars are born in clouds of dense dust and gas, which tend to obscure the stars in optical wavelengths. An instrument like APEX that records images in radio wavelengths can capture details that our eyes cannot see.
In their observations of the Orion complex, Stanke and his colleagues were able to track molecular outflows, large winds driven into the interstellar space of star-forming processes, and map molecular gas in different nebulae.
The scientists also found a nebula that no one had ever seen before, almost perfectly circular, suggesting a spherical cloud without stars. They called this object the Cow Nebula orb and believe that it could be used to study cloud structure and dynamics, although more observations need to be made to better understand its nature and properties.
The work of the team has been accepted Astronomy and astrophysics and is available on arXiv.
Versions in wallpaper size of the composite and only radio images of the Flame Mist can be found on ESO's website.