Astronomers have found massive stars forming in the "empty" outskirts of a galaxy, 100,000 light-years from its center.
March 31, 2026
Original Paper
Star Formation Beyond the Optical Disk : The Low-Density Outskirts of NGC2090
arXiv · 2603.28395
The Takeaway
It was previously thought that the edges of galaxies were too thin and gas-poor to create new stars, but NGC 2090 is birthing them in a massive "no-man's-land" far beyond its visible disk. This discovery shows that galaxies are much larger than they appear and are actively growing by birthing stars in the surrounding vacuum.
From the abstract
We present a far-ultraviolet (FUV) analysis of the star-forming complexes (SFCs) in the nearby spiral galaxy NGC\,2090, based on observations from the Ultraviolet Imaging Telescope (UVIT), and compare it with emission from the optical and infrared bands. NGC\,2090 exhibits prominent star formation in its extended outer disk, with FUV emission traced out to $\sim$30 kpc, far beyond the truncation of the old stellar disk at $\sim$5 kpc. It is classified as an extended UV (XUV) disk galaxy. We iden