Spatial Distribution of NGC 346 Stars Annotated

NASA’s Hubble Space Telescope Finds Window Into Early Universe

L’amas d’étoiles massif NGC 346, situé dans le Petit Nuage de Magellan, a longtemps intrigué les astronomes par sa forme inhabituelle. Maintenant, des chercheurs utilisant deux méthodes distinctes ont déterminé que cette forme est due en partie aux étoiles et au gaz qui se dirigent en spirale vers le centre de cet amas dans un mouvement semblable à celui d’une rivière. La spirale rouge superposée à NGC 346 retrace le mouvement des étoiles et du gaz vers le centre. Les scientifiques disent que ce mouvement en spirale est le moyen le plus efficace d’alimenter la formation d’étoiles de l’extérieur vers le centre de l’amas. Crédit : NASA, ESA, Andi James (STScI)

Les étoiles sont les machines qui façonnent l’univers, mais les chercheurs ne comprennent pas encore complètement comment elles se forment. Les scientifiques se sont tournés vers le Petit Nuage de Magellan, une galaxie satellite du

voie Lactée
La Voie lactée est la galaxie qui contient notre système solaire et porte le nom de son apparition depuis la Terre. C’est une galaxie spirale barrée qui contient environ 100 à 400 milliards d’étoiles et qui mesure entre 150 000 et 200 000 années-lumière de diamètre.

” data-gt-translate-attributes=”[{” attribute=””>Milky Way, to understand the frenzied “baby boom” of star birth that occurred early in the universe’s history. This nearby galaxy has a simpler chemical composition than the Milky Way, which makes it similar to the galaxies found in the younger universe, when heavier elements were less abundant. As a result, it can serve as a proxy for the early universe.

Two separate research studies – the first with the

Spatial Distribution of NGC 346 Stars

The massive star cluster NGC 346, located in the Small Magellanic Cloud, has long intrigued astronomers with its unusual shape. Now researchers using two separate methods have determined that this shape is partly due to stars and gas spiraling into the center of this cluster in a river-like motion. Credit: NASA, ESA, Andi James (STScI)

NASA’s Hubble Finds Spiraling Stars, Providing Window into Early Universe

Spirals are prevalent in nature — from the whirlpool of a hurricane, to pinwheel-shaped protoplanetary disks around newborn stars, to the vast realms of spiral galaxies across our universe.

Now astronomers are bemused to discover young stars that are spiraling into the center of a massive cluster of stars in the Small Magellanic Cloud, a satellite galaxy of the Milky Way.

The outer arm of the spiral in this massive, oddly shaped stellar nursery called NGC 346 may be feeding star formation in a river-like motion of gas and stars. Scientists say that this is an efficient way to fuel star birth.

The Small Magellanic Cloud has a simpler chemical composition than the Milky Way. This makes it similar to the galaxies found in the younger universe when heavier elements were more scarce. Because of this, the stars in the Small Magellanic Cloud burn hotter and therefore run out of their fuel faster than in our Milky Way.

Even though it can serve as a proxy for the early universe, the Small Magellanic Cloud is also one of our closest galactic neighbors, at just 200,000 light-years away.

Discovering how stars form in the Small Magellanic Cloud offers a new twist on how a firestorm of star birth may have occurred early in the universe’s history, when it was undergoing a “baby boom” about 2 to 3 billion years after the big bang (the universe is now 13.8 billion years old).

According to the new findings, the process of star formation there is similar to that in our own Milky Way.

NGC 346 boasts the mass of 50,000 Suns, despite being only 150 light-years in diameter. Its intriguing shape and rapid star-formation rate have baffled astronomers. It required the combined power of

However, this cluster is relatively far away, inside a neighboring galaxy. This means the amount of observed motion from our vantage point is very small and therefore difficult to measure. These extraordinarily precise observations were possible only because of Hubble’s outstanding resolution and high sensitivity. Additionally, Hubble’s three-decade-long history of observations provides a baseline for astronomers to follow minute celestial motions over time.

The second team, led by Peter Zeidler of AURA/STScI for the European Space Agency (ESA), used the ground-based VLT’s Multi Unit Spectroscopic Explorer (

Half of the Hubble data for this study of NGC 346 is archival, with the first observations taken 11 years ago. These observations were recently repeated to trace the motion of the stars over time. Given the telescope’s longevity, more than 32 years of astronomical data are now contained in the Hubble data archive, which can power unprecedented, long-term studies.

“The Hubble archive is really a gold mine,” said Sabbi. “There are so many interesting star-forming regions that Hubble has observed over the years. Given that Hubble is performing so well, we can actually repeat these observations. This can really advance our understanding of star formation.”

The teams’ findings appear today (September 8) in The Astrophysical Journal.

Reference: “The Internal Line-of-Sight Kinematics of NGC 346: The Rotation of the Core Region” by Peter Zeidler, Elena Sabbi and Antonella Nota, 8 September 2022, The Astrophysical Journal.
DOI: 10.3847/1538-4357/ac8004

Observations with NASA’s

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