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.

T. Hung et al 2018 ApJS 238 15

A systematic selection of tidal disruption events (TDEs) in the wide-area (4800 deg²) view of the iPTF experiment finds 2 confirmed TDEs, suggesting a TDE per galaxy rate of ~1.7 x 10^-4 per galaxy per year.

Eva H. L. Bodman et al 2018 AJ 156 173

Compositional features of a dusty tail trailing a disintegrating planet will be detectable by the James Webb Space Telescope for transit depths of ~0.3% in the visible range, allowing us to learn about planet interiors.

P. Bennet et al 2018 ApJL 866 L11

Observations of two new ultra-diffuse galaxies (UDGs), suggest that galaxy interactions could form some UDGs by 1) expanding ordinary dwarf galaxies, or 2) causing a UDG to collapse out of tidal material.

V. M. S. Carrasco et al 2018 ApJ 865 88

The ratio of sunspot umbra to penumbra is found to be roughly the same for sunspots during the Maunder Minimum — a prolonged period of low solar activity that occurred between 1645 and 1715 — as those today.

Sanjaya Paudel et al 2018 AJ 156 166

Deep optical imaging of the gas-rich merging dwarf system KUG 0200-096 reveals a young stellar clump with a stellar mass of 2 × 10⁷ M_⊙ at the tip of the faint tidal tail — possibly a tidal dwarf galaxy.