Local Bubble
The Local Bubble, or Local Cavity,[1] is where we are in our galaxy. It is a relative cavity in the interstellar medium (ISM) of the Orion Arm in the Milky Way. It contains among others, the Local Interstellar Cloud, which contains the Solar System, and the G-Cloud. It is at least 300 light years across. It has a neutral-hydrogen density of about 0.05 atoms/cm3, or about one tenth of the average for the ISM in the Milky Way (0.5 atoms/cm3)
The exceptionally sparse gas of the Local Bubble is the result of supernovae that exploded within the past ten to twenty million years. The gas is still in an excited state, emitting in the X-ray band.[2][3]
Local Bubble Media
Model of space near the Sun: (grey) Local Bubble, (magenta) molecular clouds, (cyan) Loop I Bubble. 
Close up on the Orion Arm, with major stellar associations (yellow), nebulae (red) and dark nebulae (grey) around the Local Bubble.
Artist's conception of the Local Bubble (containing the Sun and Beta Canis Majoris) and the Loop I Bubble (containing Antares)
The Local Bubble has 7 regions of star-forming molecular clouds on its surface which has an average radius of 500 light-years according to its determination from the three-dimensional extinction map.
As the bubble expands it sweeps interstellar gas and dust which collapse to form new stars on its surface but not inside. The Sun entered the bubble around five million years ago.
Local stars in the galactic plane (click for rotation)
References
- ↑ Abt, Helmut A. (2015), "Hot gaseous stellar disks avoid regions of low interstellar densities", Publications of the Astronomical Society of the Pacific, 127 (958): 1218–1225, Bibcode:2015PASP..127.1218A, doi:10.1086/684436, S2CID 124774683
- ↑ Local chimney and superbubbles, Solstation.com
- ↑ NASA-funded X-ray Instrument Settles Interstellar Debate, www.nasa.gov