Researchers have found a rare example of a blue straggler star in the process of formation, providing direct evidence for the formation of these puzzling stars through ongoing mass transfer in a binary system.

In a sample of 171 new dual active galactic nuclei, four triplets, and one quadruplet drawn from a catalog of nearly a million quasars, researchers find that roughly 16% of targets exhibit tidal features.

Researchers find a system inclination of 41.8 degrees for WR 104; this result is at odds with previous interpretations of the system’s dust plume, but a new geometric model reconciles these results.

The observed steepening of the cosmic-ray spectrum at ~4 PeV could be a global or local feature; a local feature could be explained by sources located ~1 kpc away with ages of 0.1–1 million years.

Using three dedicated telescopes and two spacecraft in the Earth–Moon environment, researchers demonstrate the abilities of an image stacking method to detect space debris.

Analysis of 10 nights of observations of Europa’s auroral emission suggests that optical auroral brightness may be a proxy for electron density variations, assuming a stable atmospheric composition and density.