C. E. Barbosa et al 2020 ApJS 247 46

A systematic study of the stellar populations of ultra-diffuse galaxies (UDGs) in the field suggests that field UDGs have more extended star formation histories than UDGs in clusters, including some forming stars now.

A. Albert et al 2020 ApJ 892 92

A search for point-like and extended sources of cosmic neutrinos using data collected by the ANTARES and IceCube neutrino telescopes revealed no sources, setting upper limits on flux, particularly around the galactic center.

Paul Michael Schenk 2020 ApJL 892 L12

Low-resolution global imaging maps of Europa’s surface obtained in 1979, 1996–1998, and 2007 by Voyager, Galileo, and New Horizons reveal no obvious surface changes related to plume activity on the satellite.

Hiromichi Tagawa et al 2020 ApJ 892 36

Models show that when collapsing gas fragments at higher densities, the central protostar avoids contraction and keeps growing via frequent stellar mergers, reaching masses as high as ~10⁵–10⁶ M_⊙.

Marina Brozović et al 2020 AJ 159 149

Ranging measurements from Arecibo observations spanning 1999 to 2016 provide high precision astrometric measurements of Jupiter’s moons Io, Europa, Ganymede, and Callisto.

Ryota Nakano and Masatoshi Hirabayashi 2020 ApJL 892 L22

Asteroid (3200) Phaethon, a source of the Geminid meteor stream, is rotating close to or above its critical rotation period; the Geminids may be the result of a past mass-shedding event from when it spun even faster.