Joss Bland-Hawthorn

About five billion years ago, the Sagittarius galaxy began falling into the Milky Way, repeatedly slicing through its disk. Scientists simulated a billion-year-old impact: it nicely reproduced the spiral arms and the warp, but not all the wave patterns in stellar motion. So other jolts must have hap

Like a restorer examining an ancient manuscript under different lights, astronomers used DESI spectroscopy and the GS3 Hunter algorithm to peer beneath the surface of the Gaia Sausage. They found not a monolith, but a palimpsest: four substructures aged 7 to 12 billion years, differing in chemical c

Peering 7.6 billion years into the past, the James Webb Space Telescope found galaxy UDS 12999—it looks like a typical present-day spiral. Yet its center is already graced with a fully mature X-shaped bulge, the telltale sign of a stellar bar's prolonged work. This implies that the crucial phase of

Analysis of images from JWST and Hubble with NIRSpec spectroscopy has revealed details of a distant disk galaxy at z=0.92. Multi-component modeling showed that an X-shaped bulge 4.5 kpc long and a bar of about 12 kpc were already present when the Universe was only 6.2 billion years old. A total stel