Haining Li et al 2018 ApJS 238 16

A search for very metal-poor ([Fe/H]<-2.0) stars in the Milky Way resulted in a sample of 10,008 stars — the largest number of candidates to date that are bright enough for high-resolution follow-up with 4–10 m telescopes.

Brett M. Morris et al 2018 AJ 156 203

Individual observations suggest starspots are co-located with bright plages in the chromosphere of a G1 star, as with the Sun; in contrast, starspots and plages do not appear to be co-located on two observed K stars.

Merrill A Roberts et al 2018 ApJ 866 14

Three internal coronal-hole jet regions, featuring different wave modes and levels of compressibility, have distinct identifying signatures detectable by the Parker Solar Probe in a mission encounter.

Matthew A. Taylor et al 2018 ApJL 867 L15

Fifteen new dwarf galaxies are discovered in the Western halo of the nearby giant elliptical galaxy NGC 5128 at projected distances of ~100–225 kpc from their giant host.

Andrew Vanderburg et al 2018 AJ 156 184

The radial-velocity signal estimated for a candidate exomoon suggests that large exomoons around directly imaged planets orbiting bright, nearby stars may be detectable with current or next generation instrumentation.

D. J. Mullan and H. P. Bais 2018 ApJ 865 101

Photosynthesis on a habitable-zone planet orbiting an M-dwarf host is less effective than on Earth by a factor of 10–100 or more during the host’s quiescent state; during flares, this can increase up to 50–60% the values on Earth.