The beautiful birth of a star has produced an exquisitely ethereal structure in interstellar space.
It’s called the Chamaeleon Infrared Nebula, located about 520 light-years away, and in a new image from the NSF NOIRLab’s International Gemini Observatory in Chile, it appears in the sky like a pale gossamer butterfly wing.
Stars are intense objects, and so too are their births. They form when dense clumps in clouds of molecular gas collapse, spinning, under their own gravity.
As they spin, material is drawn into an accretion disk that feeds into the growing protostar – the mass of gas that will become the star.
As the protostar grows, it starts to produce a powerful stellar wind, and material falling into the protostar starts to interact with its magnetic fields. This material flows along magnetic field lines to the poles, where it is blasted into space in the form of powerful plasma jets.
This is what astronomers think we are looking at with the Chamaeleon Infrared Nebula (so-named because it glows brightly in infrared, although this image is in optical wavelengths).
The ‘wing’ is a tunnel carved out of the cloud of gas around the star by one of the jets from the protostar.
The Chamaeleon Infrared Nebula. (International Gemini Observatory/NOIRLab/NSF/AURA)
The baby star’s light then illuminates this cavity from within, reflecting off the gas structures to create what we call a reflection nebula.
The star itself is obscured by a vertical dark band, seen at the narrowest point.
This, according to our understanding, is the protostar’s accretion disk, viewed edge-on. A red blob to the right of this disk from our perspective is a point at which a blob of material ejected from the star slammed into the surrounding gas.
This process creates short-lived, bright patches of nebulosity known as Herbig-Haro objects. This particular one is known as HH 909A. Astronomers watching carefully can observe Herbig-Haro objects change on a timescale of just a few years.
Those winds and jets from the star have another effect, too. They blow away material from around the protostar, eventually cutting off its supply of gas and therefore its ability to grow further.
By that time, the star should have gained enough mass to generate sufficient pressure and heat and its core to ignite nuclear fusion, kicking it onto the main sequence as a full star.
