Star formation near the Sun is driven by expansion of the Local Bubble
  For decades we have known that the Sun lies within the Local Bubble, a cavity
of low-density, high-temperature plasma surrounded by a shell of cold, neutral
gas and dust. However, the precise shape and extent of this shell, the impetus
and timescale for its formation, and its relationship to nearby star formation
have remained uncertain, largely due to low-resolution models of the local
interstellar medium. Leveraging new spatial and dynamical constraints from the
Gaia space mission, here we report an analysis of the 3D positions, shapes, and
motions of dense gas and young stars within 200 pc of the Sun. We find that
nearly all the star-forming complexes in the solar vicinity lie on the surface
of the Local Bubble and that their young stars show outward expansion mainly
perpendicular to the bubble's surface. Tracebacks of these young stars' motions
support a scenario where the origin of the Local Bubble was a burst of stellar
birth and then death (supernovae) taking place near the bubble's center
beginning 14 Myr ago. The expansion of the Local Bubble created by the
supernovae swept up the ambient interstellar medium into an extended shell that
has now fragmented and collapsed into the most prominent nearby molecular
clouds, in turn providing robust observational support for the theory of
supernova-driven star formation.
