constellation Tucana Archivi

Hubble spots stellar sculptors at work in a nearby galaxy: a new image of the star cluster NGC 346

In anticipation of the upcoming 35th anniversary of the NASA/ESA Hubble Space Telescope, ESA/Hubble is kicking off the celebrations with a new image of the star cluster NGC 346, featuring new data and processing techniques. This prolific star factory is in the Small Magellanic Cloud, one of the largest of the Milky Way’s satellite galaxies.

As part of ESA/Hubble’s 35th anniversary celebrations, a new image series is being shared to revisit stunning Hubble targets that were previously released. This image series combines new processing techniques with the latest data from Hubble to re-release these cosmic scenes for the public to enjoy.

This new image showcases the dazzling young star cluster NGC 346. Although several images of NGC 346 have been released previously, this view includes new data and is the first to combine Hubble observations made at infrared, optical, and ultraviolet wavelengths into an intricately detailed view of this vibrant star-forming factory.

NGC 346 is located in the Small Magellanic Cloud, a satellite galaxy of the Milky Way that lies 200 000 light-years away in the constellation Tucana. The Small Magellanic Cloud is less rich in elements heavier than helium — what astronomers call metals — than the Milky Way. This makes conditions in the galaxy similar to what existed in the early universe.

NGC 346 is home to more than 2500 newborn stars. The cluster’s most massive stars, which are many times more massive than our Sun, blaze with an intense blue light in this image. The glowing pink nebula and snakelike dark clouds are sculpted by the luminous stars in the cluster.

Hubble’s exquisite sensitivity and resolution were instrumental in uncovering the secrets of NGC 346’s star formation. Using two sets of observations taken 11 years apart, researchers traced the motions of NGC 346’s stars, revealing them to be spiralling in toward the centre of the cluster. This spiralling motion arises from a stream of gas from the outside of the cluster that fuels star formation in the centre of the turbulent cloud.

The inhabitants of this cluster are stellar sculptors, carving out a bubble from the nebula. NGC 346’s hot, massive stars produce intense radiation and fierce stellar winds that pummel the billowing gas of their birthplace and begin to disperse the surrounding nebula.

The nebula, named N66, is the brightest example of an H II (pronounced ‘H-two’) region in the Small Magellanic Cloud. H II regions are set aglow by ultraviolet light from hot young stars like those in NGC 346. The presence of the brilliant nebula indicates the young age of the star cluster, as an H II region shines only as long as the stars that power it — a mere few million years for the massive stars pictured here.

This image was developed from multiple Hubble observing programmes: #10248 (PI: Antonella Nota), #12940 (PI: Phillip Massey), #13680 (PI: Elena Sabbi), #15891 (PI: Claire Murray), and #17118 (PI: Claire Murray).

A star cluster within a nebula. The background is filled with thin, pale blue clouds. Parts are thicker and pinker in colour. The cluster is made up of bright blue stars that illuminate the nebula around them. Large arcs of dense dust curve around, before and behind the clustered stars, pressed together by the stars’ radiation. Behind the clouds of the nebula can be seen large numbers of orange stars. — The Hubble Space Telescope spots stellar sculptors at work in a nearby galaxy: a new image of the star cluster NGC 346. This new image showcases NGC 346, a dazzling young star cluster in the Small Magellanic Cloud. The Small Magellanic Cloud is a satellite galaxy of the Milky Way, located 200 000 light-years away in the constellation Tucana. The Small Magellanic Cloud is less rich in elements heavier than helium — what astronomers call metals — than the Milky Way. This makes conditions in the galaxy similar to what existed in the early universe. Although several images of NGC 346 have been released previously, this view includes new data and is the first to combine Hubble observations made at infrared, optical, and ultraviolet wavelengths into an intricately detailed view of this vibrant star-forming factory. NGC 346 is home to more than 2500 newborn stars. The cluster’s most massive stars, which are many times more massive than our Sun, blaze with an intense blue light in this image. The glowing pink nebula and snakelike dark clouds are the remnant of the birthsite of the stars in the cluster. The inhabitants of this cluster are stellar sculptors, carving out a bubble from the nebula. NGC 346’s hot, massive stars produce intense radiation and fierce stellar winds that pummel the billowing gas of their birthplace and begin to disperse the surrounding nebula. The nebula, named N66, is the brightest example of an H II (pronounced ‘H-two’) region in the Small Magellanic Cloud. H II regions are set aglow by ultraviolet light from hot young stars like those in NGC 346. The presence of the brilliant nebula indicates the young age of the star cluster, as an H II region shines only as long as the stars that power it — a mere few million years for the massive stars pictured here. Credit: ESA/Hubble & NASA, A. Nota, P. Massey, E. Sabbi, C. Murray, M. Zamani (ESA/Hubble)

Press release from ESA Hubble.

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Webb’s MIRI captures an ethereal view of NGC 346

One of the greatest strengths of the NASA/ESA/CSA James Webb Space Telescope is its ability to give astronomers detailed views of areas where new stars are being born. The latest example, showcased here in a new image from Webb’s Mid-Infrared Instrument (MIRI), is NGC 346 – the brightest and largest star-forming region in the Small Magellanic Cloud.

NGC 346 (MIRI image) — This new infrared image of NGC 346 from the NASA/ESA/CSA James Webb Space Telescope’s Mid-Infrared Instrument (MIRI) traces emission from cool gas and dust. In this image blue represents silicates and sooty chemical molecules known as polycyclic aromatic hydrocarbons, or PAHs. More diffuse red emission shines from warm dust heated by the brightest and most massive stars in the heart of the region. Bright patches and filaments mark areas with abundant numbers of protostars.
This image includes 7.7-micron light shown in blue, 10 microns in cyan, 11.3 microns in green, 15 microns in yellow, and 21 microns in red (770W, 1000W, 1130W, 1500W, and 2100W filters, respectively).
Credit: NASA, ESA, CSA, N. Habel (JPL), P. Kavanagh (Maynooth University)

The Small Magellanic Cloud (SMC) is a satellite galaxy of the Milky Way, visible to the unaided eye in the southern constellation Tucana. This small companion galaxy is more primitive than the Milky Way in that it possesses fewer heavy elements, which are forged in stars through nuclear fusion and supernova explosions, compared to our own galaxy.

Since cosmic dust is formed from heavy elements like silicon and oxygen, scientists expected the SMC to lack significant amounts of dust. However the new MIRI image, as well as a previous image of NGC 346 from Webb’s Near-Infrared Camera released in January, show ample dust within this region.

In this representative-colour image, blue tendrils trace emission from material that includes dusty silicates and sooty chemical molecules known as polycyclic aromatic hydrocarbons, or PAHs. More diffuse red emission shines from warm dust heated by the brightest and most massive stars in the heart of the region. An arc at the centre left may be a reflection of light from the star near the arc’s centre (similar, fainter arcs appear associated with stars at lower left and upper right). Lastly, bright patches and filaments mark areas with abundant numbers of protostars. The research team has detected 1,001 pinpoint sources of light, most of them young stars still embedded in their dusty cocoons.

By combining Webb data in both the near-infrared and mid-infrared, astronomers are able to take a fuller census of the stars and protostars within this dynamic region. The results have implications for our understanding of galaxies that existed billions of years ago, during an era in the universe known as “cosmic noon,” when star formation was at its peak and heavy element concentrations were lower, as seen in the SMC.

This new image taken by Webb’s Mid-Infrared Instrument (MIRI) complements Webb’s view of NGC 346 as seen by the (NIRCam), released in January 2023.

NGC 346 (MIRI image, annotated) — This new infrared image of NGC 346 from the NASA/ESA/CSA James Webb Space Telescope’s Mid-Infrared Instrument (MIRI) traces emission from cool gas and dust. In this image blue represents silicates and sooty chemical molecules known as polycyclic aromatic hydrocarbons, or PAHs. More diffuse red emission shines from warm dust heated by the brightest and most massive stars in the heart of the region. Bright patches and filaments mark areas with abundant numbers of protostars.
This image includes 7.7-micron light shown in blue, 10 microns in cyan, 11.3 microns in green, 15 microns in yellow, and 21 microns in red (770W, 1000W, 1130W, 1500W, and 2100W filters, respectively).
Credit: NASA, ESA, CSA, N. Habel (JPL), P. Kavanagh (Maynooth University)

NGC 346: Webb Uncovers Star Formation in Cluster’s Dusty Ribbons

Press release from ESA Webb.

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