Megan Bedell et al 2018 ApJ 865 68

The C/O and Mg/Si ratios in solar-metallicity stars are measured to be homogeneous to within 10% throughout the solar neighborhood, implying that exoplanets may exhibit less compositional diversity than previously thought.

Nick Indriolo et al 2018 ApJL 865 L18

Orion BN, an object with large proper motion and radial velocity relative to its formation region, shows no evidence of hot water, disfavoring the scenario in which it was accelerated while deeply embedded in molecular gas.

Krzysztof Goździewski and Cezary Migaszewski 2018 ApJS 238 6

Models of the HR 8799 planetary system — with four detected ~10 M_Jup planets in wide orbits up to ~70 AU — confirm the planets are likely involved in a dynamically robust Laplace 8e:4d:2c:1b resonance chain.

Samantha K. Trumbo et al 2018 AJ 156 161

New ALMA observations comprise the first spatially resolved thermal data set with complete coverage of Europa’s surface, capturing spatially localized thermal variations on the scale of geologic and compositional units.

Catherine Zucker et al 2018 ApJ 864 153

A standardized analysis of the physical properties of large-scale filaments in our galaxy reveal three broad categories of filaments, which could indicate different formation mechanisms or histories.

Ozge Ozgurel et al 2018 ApJL 865 L16

Models of metals’ journey through Europa’s ice are consistent with the assumption that sodium and potassium come from the sputtering of materials issued from its underlying ocean and exposed by resurfacing events.