H. Abdalla et al 2021 ApJ 918 17
A search for very-high-energy gamma rays generated by dark matter comes up short, ruling out dark-matter models with masses greater than 300 billion electron volts as the source of unidentified gamma-ray detections.
Zhenyong Hou et al 2021 ApJL 918 L20
Astronomers have discovered coronal microjets — sites of small-scale plasma ejection likely caused by magnetic reconnection — just 1.2 Earth radii long and with lifetimes of less than five minutes, on average.
Perianne E. Johnson et al 2021 Planet. Sci. J. 2 194
Models show that true polar wander — a change in the location of an object’s poles — may be responsible for the present-day location of Sputnik Planitia, which makes up part of Pluto’s distinctive heart-shaped feature.
Alison Duck et al 2021 AJ 162 136
A joint analysis of data from three space telescopes yields order-of-magnitude improvements in transit-time uncertainties for four sub-Neptune exoplanets that are potential targets for future space telescopes.
C. Knight et al 2021 ApJ 918 8
Stratospheric and space observations of sooty molecules called polycyclic aromatic hydrocarbons reveal that these ubiquitous molecules are larger and more ionized near the stars in reflection nebulae.
O. Muñoz et al 2021 ApJS 256 17
Laboratory studies of forsterite — a type of silicate mineral — show that assuming spherical dust grains when modeling polarization results in large errors in the sizes and composition of dust particles.