Young spiralling stars shed new light on stellar birth in early Universe

Astronomers, using the NASA/ESA Hubble Space Telescope, have discovered young stars spiralling into the centre of a massive cluster of stars in the Small Magellanic Cloud, a small galaxy about 200,000 light-years away that orbits our Milky Way galaxy.

Researchers believe that the outer arm of the spiral in this huge, oddly shaped stellar nursery, called NGC 346, may be feeding star formation in a river-like motion of gas and stars

Boasting the mass of 50,000 Suns, NGC 346's intriguing shape and rapid star formation rate have puzzled astronomers. It took the combined power of Hubble and the European Southern Observatory's Very Large Telescope (VLT) to unravel the behaviour of this mysterious-looking stellar nesting ground.

1/ Astronomers using @HUBBLE_space have discovered young stars spiralling into a stellar cluster in the Small Magellanic Cloud. The spiral's outer arm, NGC 346, may be feeding star formation, shedding new light on stellar birth.Full story: https://t.co/UaWESijpfV 👇 pic.twitter.com/u52g7qbfk4

— HUBBLE (@HUBBLE_space) September 8, 2022

To determine the motion of the stars in NGC 346, researchers, led by Elena Sabbi of the Space Telescope Science Institute in Baltimore, measured the changes in the stars’ positions over 11 years. With an average velocity of 3200 kilometres per hour, stars in this region move 320 million kilometres in 11 years - about twice the distance between Earth and the Sun.

Another team, led by Peter Zeidler of AURA/STScI for the European Space Agency, used the ground-based VLT's Multi Unit Spectroscopic Explorer (MUSE) instrument to measure radial velocity, which determines whether an object is approaching or receding from an observer.

"What was really amazing is that we used two completely different methods with different facilities and basically we came to the same conclusion independently," said Zeidler.

This discovery sheds new light on star birth may have occurred early in the history of the Universe. The teams' findings are published in the Astrophysical Journal.

"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," said Sabbi.