William Janesh et al 2019 AJ 157 183
Imaging of 23 ultracompact high-velocity clouds has revealed five objects that are likely stellar counterparts, suggesting that five of these clouds are dwarf galaxies in or near the Local Group.
Yan-Rong Li et al 2019 ApJS 241 33
Optical monitoring of Ark 120, a nearby radio-quiet active galactic nucleus, reveals a 20-year periodicity that potentially indicates this galaxy hosts a sub-parsec supermassive black hole binary.
Sebastien Guillot et al 2019 ApJ 874 175
Hubble Space Telescope observations of the ~3 × 108-year-old, slow, isolated, rotation-powered pulsar PSR J2144–3933 yield no detection — indicating that, at T < 42,000 K, this is the coldest known neutron star.
Diana Dragomir et al 2019 ApJL 875 L7
TESS’s recent discoveries include HD 21749b, a sub-Neptune in a 36 day orbit around a bright and nearby K dwarf, and HD 21749c, the first Earth-size (R ~ 0.89 Earth radii) planet that TESS has found.
Yumi Bamba et al 2019 ApJ 874 73
The largest magnetic storm in solar cycle 24 was caused by a fast coronal mass ejection thatmay have been triggered by a small magnetic disturbance generating a tiny precursor brightening at the time of a C2.4 flare.
Arjun Dey et al 2019 AJ 157 168
The DESI Legacy Imaging Surveys are a combination of three public projects that will jointly image ~14,000 deg2 of the extragalactic sky visible from the northern hemisphere in three optical bands.