Marshall C. Johnson et al 2018 AJ 155 100
The hot Jupiter KELT-21b transits a star that may have two stellar companions of ~0.12 solar masses. KELT-21b may be one of only a handful of known transiting planets in hierarchical triple stellar systems.
K. E. Lockhart et al 2018 ApJ 854 121
Infrared observations of M31’s nucleus suggest that old stellar eccentric disk orbiting the supermassive black hole slowly precesses, causing stellar winds to collide and shock and fueling episodic star formation.
Luke Hindson et al 2018 ApJS 234 29
VLA observations of 40 nearby dwarf galaxies suggest that radio continuum emission at centimeter wavelengths has the promise of being a largely extinction-free probe of star formation in dwarf galaxies.
Yuan Li et al 2018 ApJ 854 91
Ram pressure in the centers of cool-core galaxy clusters can reduce the velocity of cold clouds and sometimes cause an offset between filaments of cold gas and young stars formed in the filament.
W. Rujopakarn et al 2018 ApJL 854 L4
Three active galactic nuclei at z ~ 3 are localized to be within compact regions of gas-rich, heavily obscured, intense nuclear star formation, supporting a picture of in situ galactic bulge and supermassive black hole formation.
Erik A. Petigura et al 2018 AJ 155 89
For some planet types (like warm super-Earths), occurrence rates do not correlate with metallicity. For others (like warm sub-Neptunes), more of these planets are found around higher metallicity stars.