Richard R. Radick et al 2018 ApJ 855 75

Patterns of variation for the Sun and 72 Sun-like stars are explored through nearly three decades of data. The Sun appears to be somewhat unusual in its comparatively smooth, regular activity cycle.

I. Martín-Navarro and M. Mezcua 2018 ApJL 855 L20

Observations of 127 low-mass galaxies indicate a loose coupling between star formation history and black hole mass, suggesting that AGN activity does not dominate baryonic cooling in low-mass galaxies.

N. Haghighipour et al 2018 ApJ 855 60

Studies of comet impacts by meter-sized bodies suggest that the activities of current main-belt comets could be driven by impacts at multiple sites, at which deep impact craters form in porous materials.

Przemek Mróz et al 2018 AJ 155 121

A candidate free-floating, Neptune-mass planet has been discovered in the galactic disk as a result of a gravitational microlensing event detected by the Optical Gravitational Lensing Experiment (OGLE).

Kyuseok Oh et al 2018 ApJS 235 4

The first 105 months of observations with the Burst Alert Telescope on board the Swift observatory resulted in a catalog of 1632 hard X-ray sources in the 14–195 keV band. 34% of the 422 new detections are AGN.

Matthew J. Holman et al 2018 ApJL 855 L6

A new dwarf planet candidate has been found by the Pan-STARRS Outer Solar System Survey, joining the small but growing set of known distant dwarf planets on metastable resonant orbits.