Local Bubble

Map showing the Sun near the edge of the Local Interstellar Cloud and Alpha Centauri about four light-years away in the neighboring G-Cloud complex

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

References

  1. 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
  2. Local chimney and superbubbles, Solstation.com
  3. NASA-funded X-ray Instrument Settles Interstellar Debate, www.nasa.gov