Modeling shows how Apophis’s response to a cloud encounter with Earth depends on the object’s particle size distribution, particle shapes, packing configurations, and interior structure.

Using a new method to detect and characterize random, rapid changes in the flux from gamma-ray pulsars, researchers found no evidence for changes above the 10% level, with certain cases ruling out changes above 1%.

A reanalysis of a stellar sample confirms that standard models of how stars spin down over time are sufficient for active stars, but weakened magnetic braking is needed to explain abrupt decreases in torque.

Analysis of a particular microlensing signal suggests that there’s no simple model of the event; instead, it requires microlensing parallax, lens orbital motion, and a magnified binary companion to the host, with xallarap.

Modeling of accretion onto black holes of varying spins suggests that all hot accretion flows will develop intermittent jets if allowed to evolve for long enough.

At a distance of 4.4 au from the Sun, interstellar object 3I/ATLAS showed no signs of emission from typical cometary species, in agreement with models that predict activity to start at smaller heliocentric distances.