An astounding image of a bubble of newly forming stars in the Large Magellanic Cloud (LMC) has been captured by the Multi Unit Spectroscopic Explorer (MUSE) instrument aboard ESO’s Very Large Telescope (VLE). Researchers hope the observation will shed light as to the mechanism by which massive new stars are formed.
The pictured section of the LMC – known as LHA 120-N 180B – which glows with striking colour in the image, is a H II (pronounced “H 2”) region – a massive cloud of interstellar ionized hydrogen where star formation has recently taken place, making it a fertile source of new stars otherwise known as a stellar nursery.
These newly formed stars are responsible for the ionization of the surrounding hydrogen – resulting in a spectacular and unmistakable sight for astronomers.
The LMC is a satellite galaxy of the Milky Way, visible mainly from the Southern Hemisphere. At only around 160,000 light-years away from the Earth, it is practically on our doorstep. As well as being close to home, the LMC’s single spiral arm appears nearly face-on, allowing us to inspect regions such as N180 B with ease.
N180 B’s distinctive shape is made up of a gargantuan bubble of ionised hydrogen surrounded by four smaller bubbles. Deep within this glowing cloud, MUSE has spotted a jet emitted by a massive fledgeling star with a mass 12 times greater than our Sun. The jet -named Herbig-Haro 1177, or HH 1177 for short – is shown in detail in this accompanying image.
This is the first time such a jet has been observed in visible light outside the Milky Way, as they are usually obscured by their dusty surroundings. However, the relatively dust-free environment of the LMC allows HH 1177 to be observed at visible wavelengths, which at nearly 33 light-years in length, is one of the longest such jets ever observed.
The jet has the potential to tell us a great deal of information about the early development of stars. The beam is highly collimated – meaning it barely spreads out as it travels – which are the type of jets that have been associated with both high and low mass stars. These type of jets are normally associated with accretion discs of stars – discs formed from material like gas and dust which is heated and compressed and subsequently falls onto the surface of the star.
Up until this point accretion discs have generally been associated with only low mass stars. The fact that these particular jets are associated with both high mass and low mass stars implies that high mass stars can form in the same way as their smaller counterparts and that disc led accretion occurs in more massive stars as well.
The researchers suggest that the high degree of collimation spotted in this observation implies the system is formed by a ‘scaled-up ‘ version of the mechanism that forms low mass stars. Thus the findings could well indicate that the physics that govern the launching of these powerful jets are independent of stellar mass.
Top of page image: This dazzling region of newly forming stars in the Large Magellanic Cloud (LMC) was captured by the Multi Unit Spectroscopic Explorer instrument on ESO’s Very Large Telescope. The relatively small amount of dust in the LMC and MUSE’s acute vision allowed intricate details of the region to be picked out in visible light (ESO, A McLeod et al)
Original research: https://www.nature.com/articles/nature25189