Roy A. Tucker et al 2021 ApJS 256 1

Activity within the stellar chromosphere or the presence of a disk of planetary debris may be the cause of the strange behavior of a short-period (6.65 days) variable star.

Young Min Seo et al 2021 ApJ 917 57

Magnetic fields threaded through the Keyhole Nebula in the Carina Nebula Complex — the most energetic star-forming region in our galaxy — are no match for the extreme stellar winds from η Carinae.

Chong Li et al 2021 ApJL 918 L2

A 3,500-light-year-long gas filament at a distance of more than 70,000 light-years has been discovered using the Five-hundred-meter Aperture Spherical radio Telescope (FAST).

Laura Venuti et al 2021 AJ 162 101

A survey of 278 young stars with masses in the 2–5 solar mass range reveals that magnetic field structures and variability, including disk-driven variability, depend on stellar mass.

A. Pusack et al 2021 Planet. Sci. J. 2 186

Observations of the inner solar system by Parker Solar Probe suggest that there may be an additional population of particles making up zodiacal dust, potentially associated with the Geminids meteoroid stream.

Norita Kawanaka and Shiu-Hang Lee 2021 ApJ 917 61

The material surrounding a supernova affects the energies of escaping cosmic rays, with interstellar-medium-like surroundings producing “softer” secondary cosmic rays and wind-like surroundings producing “harder” secondary cosmic rays.