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Stellar nursery is a cliffhanger

Lagoon Nebula's 'Southern Cliff'

The Lagoon Nebula is a glorious cloudscape of dust and gas surrounding a nursery of intermediate- and low-mass stars. This image shows just a small part of it, a region called the 'Southern Cliff'.

  • Lagoon Nebula is a nursery of intermediate- and low-mass stars
  • Located somewhere between 4,000 and 6,000 light-years from Earth
  • This image shows the region known as the ‘Southern Cliff’

AN ALL-TIME FAVOURITE OF SKYWATCHERS, the Lagoon Nebula (Messier 8 or M8) is among the most striking examples of a ‘stellar nursery’ in our neighbourhood of the Milky Way galaxy. Visible through small telescopes and binoculars its fuzzy glow reveals the type of chaotic environment where new stars are born.

Argentinean astronomers Julia Arias (Universidad de La Serena) and Rodolfo Barbá (Universidad de La Serena and ICATE-CONICET) used the Gemini South telescope in Chile to obtain a dramatic new image of the Lagoon.

Actually, since M8 is located some 5,000 light-years away, the multi-hued scene is a “flashback”…as its photons had to travel through space for that same number of years before they reached Gemini South’s gigantic 8-metre mirror.

The picture reveals a glorious cloudscape of dust and gas surrounding a nursery of intermediate- and low-mass stars.

The image above shows only part of the Lagoon…a region astronomers sometimes call the ‘Southern Cliff’ because it resembles a sharp drop-off. Beyond the “cliff,” light from a spattering of young background stars in the upper left of the image shines through the cloudscape.

The full Lagoon Nebula

The full Lagoon Nebula is a vast region of gas, dust and stars, spanning 110 by 50 light-years.

The glow from growing stars

Arias and Barbá obtained the imaging data to explore the evolutionary relationship between the newborn stars and what are known as Herbig-Haro (HH) objects. HH objects form when young stars eject large amounts of fast-moving gas as they grow.

This gas ploughs into the surrounding nebula, producing bright shock fronts that glow as the gas is heated by friction and surrounding gas is excited by the high-energy radiation of nearby hot stars.

The researchers found a dozen HH objects in the image, range in size from about 1/10,000th of a light-year to 4.6 light-years (the latter being a little greater than the distance from the Sun to its nearest neighbour Proxima Centauri).

Detail image of the Lagoon Nebula's 'Southern Cliff'

Newborn stars are embedded in the tips of these thick dusty clouds.

Most of the newborn stars are embedded in the tips of thick dusty clouds, which have the appearance of bright-rimmed pillars.

The Lagoon Nebula is located in the direction of the constellation Sagittarius in the southern Milky Way. Viewed through large amateur telescopes, it appears as a pale ghostly glow with a touch of pink.

The astronomers used selective filters to reveal characteristics of the gas, and so the colours shown are not representative of the real colour. For example, light from the far-red end of the spectrum, beyond what the eye can see, appears blue in this image.

Download the full-size (5852 x 2667-pixel) image here.

International Facility

The Gemini Observatory is an international collaboration with two identical 8-metre telescopes. The Frederick C. Gillett Gemini Telescope is located on Mauna Kea, Hawai’i (Gemini North) and the other telescope on Cerro Pachón in central Chile (Gemini South). Together they provide coverage of the entire sky.

The Observatory is operated as a partnership of research agencies from seven countries: the US National Science Foundation (NSF), the UK Science and Technology Facilities Council (STFC), the Canadian National Research Council (NRC), the Chilean Comisión Nacional de Investigación Cientifica y Tecnológica (CONICYT), the Australian Research Council (ARC), the Argentinean Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) and the Brazilian Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq).

Adapted from information issued by Gemini Observatory. ‘Southern Cliff’ image courtesy Gemini Observatory / AURA / Julia Arias (Universidad de La Serena) and Rodolfo Barbá (Universidad de La Serena and ICATE-CONICET). Full Lagoon image courtesy ESO / S. Guisard.

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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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Dive into the Lagoon Nebula

Close-up shot of the centre of the Lagoon Nebula

This close-up shot of the centre of the Lagoon Nebula clearly shows the delicate structures formed when the powerful radiation of young stars interacts with the hydrogen cloud from which they formed.

  • Lagoon Nebula, a famous “starbirth” region
  • Located 4,000 to 5,000 light-years away
  • Evidence that stars and planets are forming within

The Advanced Camera for Surveys (ACS) on Hubble Space Telescope has captured a dramatic view of gas and dust sculpted by intense radiation from hot young stars deep in the heart of the Lagoon Nebula (also known as Messier 8).

This spectacular object is named after the wide, lagoon-shaped dust lane that crosses the glowing gas of the nebula.

This dust lane structure is prominent in wide-field images, but cannot be seen in this close-up. However the strange billowing shapes and sandy texture visible in this image make the Lagoon Nebula’s watery name eerily appropriate from this viewpoint too.

Here’s a video pan across the new Hubble image:

Located 4,000 to 5,000 light-years away, Messier 8 is a huge region of star birth that stretches across 100 light-years. Clouds of hydrogen gas are slowly collapsing to form new stars, whose bright ultraviolet rays then light up the surrounding gas in a distinctive shade of red.

See the full-size, high-resolution version of the image here.

Wide-field image of the Lagoon Nebula

A wide-field image shows the entirety of the Lagoon Nebula. The Hubble image focuses on a tiny portion in the heart of the Nebula, just below and to the right of centre.

The wispy tendrils and beach-like features of the nebula are not caused by the ebb and flow of tides, but rather by ultraviolet radiation’s ability to erode and disperse the gas and dust into the distinctive shapes that we see.

In recent years astronomers probing the secrets of the Lagoon Nebula have found the first unambiguous evidence that star formation by accumulation of matter from the gas cloud is ongoing in this region.

Young stars that are still surrounded by a swirling cloud of gas and dust occasionally shoot out long tendrils of matter from their poles. Several examples of these jets, known as Herbig-Haro objects, have been found in this nebula in the last five years, providing strong support for astronomers’ theories about star formation in such hydrogen-rich regions.

Watch this impressive zoom-in video, which takes us from the outer reaches of the Milky Way and into the Lagoon:

The Lagoon Nebula is faintly visible to the naked eye on dark nights as a small patch of grey in the heart of the Milky Way. Without a telescope, the nebula looks underwhelming because human eyes are unable to distinguish clearly between colours at low light levels.

Charles Messier, the 18th century French astronomer, studied the nebula and included it in his famous astronomical catalogue, from which the nebula’s alternative name comes. But his relatively small refracting telescope would only have hinted at the dramatic structures and colours now visible thanks to Hubble.

Adapted from information issued by Spacetelescope.org / NASA / A. Caulet (ST-ECF, ESA) / Hunter Wilson.

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