The barred spiral galaxy NGC 6872 has ranked among the biggest stellar systems for decades. Now a team of astronomers has crowned it the largest-known spiral, based on archival data from NASA's Galaxy Evolution Explorer (GALEX) mission.
Newly released NASA Hubble Space Telescope images of a vast debris disk encircling the nearby star Fomalhaut and a mysterious planet circling it may provide forensic evidence of a titanic planetary disruption in the system.
Back in January, a new X-ray source flared and rapidly brightened in the Andromeda galaxy (M31). It became the target of an intense observing campaign by orbiting X-ray telescopes -- including NASA's Swift.