Hubble Finds Spiraling Stars (NGC 346)

bystander · Post by **bystander** » Thu Sep 08, 2022 3:12 pm

Spiraling Stars Provide a Window into the Early Universe
ESA Hubble Science Release | 2022 Sep 08

Click to view full size image 1 or image 2
Credit: NASA, ESA, Andi James (STScI)
Astronomers have been bemused to find young stars spiralling into the centre 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 huge, oddly shaped stellar nursery — called NGC 346 — may be feeding star formation in a river-like motion of gas and stars. This is an efficient way to fuel star birth, researchers say.

The Small Magellanic Cloud has a simpler chemical composition than the Milky Way, making 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 so run out of their fuel faster than in our Milky Way. Though a proxy for the early universe, at 200 000 light-years away the Small Magellanic Cloud is also one of our closest galactic neighbours.

Learning 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 history of the Universe, when it was undergoing a 'baby boom' about two to three billion years after the Big Bang (the Universe is now 13.8 billion years old).

The new results show that the process of star formation there is similar to that in our own Milky Way. ...

NASA's Hubble Finds Spiraling Stars,
Providing Window into Early Universe
NASA | GSFC | STScI | HubbleSite | 2022 Sep 08

The Internal Proper Motion Kinematics of NGC 346:
Past Formation and Future Evolution ~ E. Sabbi et al

Astrophysical Journal 936(2):135 (2022 Sep 10) DOI: 10.3847/1538-4357/ac8005
arXiv > astro-ph > arXiv:2209.03215 > 07 Sep 2022

The Internal Line-of-Sight Kinematics of NGC 346:
The Rotation of the Core Region ~ Peter Zeidler et al

Astrophysical Journal 936(2):136 (2022 Sep 10) DOI: 10.3847/1538-4357/ac8004
arXiv > astro-ph > arXiv:2209.03237 > 07 Sep 2022

Ann · Post by **Ann** » Sat Sep 10, 2022 5:41 am

I couldn't quite picture the spiraling stars, because this part had me stumped:

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.

The outer arm of what spiral? The spiral of the Small Magellanic Cloud itself? But the SMC isn't a spiral!