RCW 106, a vast cloud of gas and dust, along with its rich and fascinating surroundings, are captured in this incredible photo from ESO’s VLT Survey Telescope (VST).
In this wide-field image from ESO’s VLT Survey Telescope wisps of gas are illuminated by massive stars that have only recently ignited and are still buried deep in thick dust clouds. Image credit: ESO.
RCW 106 is a so-called H II region located in the southern constellation Norma, approximately 12,000 light-years away from Earth.
H II regions clouds of hydrogen gas that are being ionized by starlight of hot, infant stars, causing them to glow and display weird and wonderful shapes.
RCW 106 itself is the red cloud above center in this VST image, although much of this giant object is hidden by dust and it is much more extensive than the visible part.
Many other unrelated objects are also visible in this image.
For example, the filaments to the right of the image are the remnants of an ancient supernova (known as SNR G332.4-00.4 or RCW 103), and the glowing red filaments (RCW 104) at the lower left surround the extremely hot Wolf–Rayet star WR 75.
Patches of dark obscuring dust are also visible across the entire cosmic landscape.
Astronomers have been studying RCW 106 for some time, although it is not the crimson clouds that draw their attention, but rather the mysterious origin of the giant stars buried within.
Although they are very bright, these stars — known as O-type stars — cannot be seen in visible-light images such as this one as the surrounding dust is too thick, but they make their presence clear in images of the region at longer wavelengths.
O-type stars may have masses many dozens of times the mass of the Sun and it is not clear how they manage to gather, and keep together, enough gas to form.
These stars likely form from the densest parts of the nebular clouds like RCW 106 and they are notoriously difficult to study.
Apart from obscuration by dust, another challenge is the brevity of an O-type star’s life. They burn through their nuclear fuel in mere tens of millions of years, while the lightest stars have lifetimes that span many tens of billions of years.
The difficulty of forming a star of this mass, and the shortness of their lifetimes, means that they are very rare – only one in every three million stars in our cosmic neighborhood is an O-type star.
