Extended stellar systems in the solar neighborhood - II. Discovery of a nearby 120{\deg} stellar stream in Gaia DR2

Understand

We report the discovery of a large, dynamically cold, coeval stellar stream that is currently traversing the immediate solar neighborhood at a distance of only 100 pc.

• The structure was identified in a wavelet decomposition of the 3D velocity space of all stars within 300 pc to the Sun.
• Its members form a highly elongated structure with a length of at least 400 pc, while its vertical extent measures only about 50 pc.
• Stars in the stream are not isotropically distributed but instead form two parallel lanes with individual local overdensities, that may correspond to a remnant core of a tidally disrupted cluster or OB association.