Diving into the Lagoon

Infrared and visible light views of the Lagoon Nebula

Comparison of infrared (top) and visible light (bottom) views of the Lagoon Nebula (Messier 8). In the infrared, the dust clouds become more transparent and the gas clouds less conspicuous. A whole host of cool red stars that are otherwise invisible are revealed.

  • Lagoon Nebula is a “stellar nursery” where stars are born
  • Located 4,000 to 5,000 light-years from Earth
  • New image taken by the world’s biggest survey telescope

A NEW INFRARED IMAGE of the Lagoon Nebula was captured as part of a five-year study of the Milky Way using ESO’s VISTA telescope at the Paranal Observatory in Chile.

This is a small piece of a much larger image of the region surrounding the nebula, which is, in turn, only one part of a huge sky survey.

Astronomers are currently using ESO’s Visible and Infrared Survey Telescope for Astronomy (VISTA) to scour the Milky Way’s central regions for variable objects and map its structure in greater detail than ever before.

This huge survey is called VISTA Variables in the Via Lactea (VVV). (Via Lactea means Milky Way in  Latin.) The new infrared image presented here was taken as part of this survey. It shows the stellar “nursery” called the Lagoon Nebula (also known as Messier 8), which is about 4,000-5,000 light-years away.

Infrared observations allow astronomers to peer through the veil of dust that prevents them from seeing celestial objects in visible light. This is because visible light, which has a wavelength that is about the same size as the dust particles, is strongly scattered, but the longer wavelength infrared light can pass through the dust largely unscathed.

VISTA, with its 4.1-metre-diameter mirror—the largest survey telescope in the world—is dedicated to surveying large areas of the sky at near-infrared wavelengths deeply and quickly. It is therefore ideally suited to studying star birth.

Watch a video zooming in on the Lagoon:

Stellar nursery

Stars typically form in large molecular clouds of gas and dust, which collapse under their own weight. The Lagoon Nebula, however, is also home to a number of much more compact regions of collapsing gas and dust, called Bok globules. These dark clouds are so dense that, even in the infrared, they can block the starlight from background stars.

But the most famous dark feature in the nebula, for which it is named, is the lagoon-shaped dust lane that winds its way through the glowing cloud of gas. Hot, young stars, which give off intense ultraviolet light, are responsible for making the nebula glow brightly.

But the Lagoon Nebula is also home to much younger stellar infants. Newborn stars detected in the nebula are so young that they are still surrounded by their natal accretion discs.

Such newborn stars occasionally eject jets of matter from their poles. When this ejected material ploughs into the surrounding gas short-lived bright streaks called Herbig-Haro objects are formed, making the newborns easy to spot.

In the last five years, several Herbig-Haro objects have been detected in the Lagoon Nebula, so the baby boom is clearly still in progress here.

Adapted from information issued by ESO / VVV / Cambridge Astronomical Survey Unit. The science team for VVV includes Dante Minniti (Universidad Catolica, Chile), Phil Lucas (University of Hertfordshire, UK), Ignacio Toledo (Universidad Catolica), and Maren Hempel (Universidad Catolica).

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