Local Bubble

Local Bubble
Superbubble
Map of open star clusters and bright stars in the Local Bubble, viewed from top down
Observation data
Distance0 ly   (0 pc)
Physical characteristics
Radius500 ly
DesignationsLocal Hot Bubble, LHB,[1] Local Bubble, Local Interstellar Bubble[2]
See also: Lists of nebulae

The Local Bubble, or Local Cavity,[3] is a relative cavity in the interstellar medium (ISM) of the Orion Arm in the Milky Way. It contains the closest of celestial neighbours and among others, the Local Interstellar Cloud (which contains the Solar System), the neighbouring G-Cloud, the Ursa Major moving group (the closest stellar moving group) and the Hyades (the nearest open cluster). It is estimated to be at least 1000 light years in size,[clarification needed] and is defined by its neutral-hydrogen density of about 0.05 atoms/cm3, or approximately one tenth of the average for the ISM in the Milky Way (0.5 atoms/cm3), and one sixth that of the Local Interstellar Cloud (0.3 atoms/cm3).[dubious – discuss][4]

The exceptionally sparse gas of the Local Bubble is the result of supernovae that exploded within the past ten to twenty million years. Geminga, a pulsar in the constellation Gemini, was once thought to be the remnant of a single supernova that created the Local Bubble, but now multiple supernovae in subgroup B1 of the Pleiades moving group are thought to have been responsible,[5] becoming a remnant supershell.[6] Other research suggests that the subgroups Lower Centaurus–Crux (LCC) and Upper Centaurus–Lupus (UCL), of the Scorpius–Centaurus association created both the local bubble and the Loop I Bubble. With LCC being responsible for the Local Bubble and UCL being responsible for the Loop I Bubble.[7] It was found that 14 to 20 supernovae originated from LCC and UCL, which could have formed these bubbles.[8]

  1. ^ Egger, Roland J.; Aschenbach, Bernd (February 1995). "Interaction of the Loop I supershell with the Local Hot Bubble". Astronomy and Astrophysics. 294 (2): L25–L28. arXiv:astro-ph/9412086. Bibcode:1995A&A...294L..25E.
  2. ^ "NAME Local Bubble". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 15 March 2014.
  3. ^ Abt, Helmut A. (December 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.
  4. ^ "Our local galactic neighborhood". Interstellar.jpl.nasa.gov. National Aeronautics and Space Administration (NASA). 8 February 2000. Archived from the original on 21 November 2013. Retrieved 23 July 2013.
  5. ^ Berghoefer, T.W.; Breitschwerdt, D. (2002). "The origin of the young stellar population in the solar neighborhood – a link to the formation of the Local Bubble?". Astronomy and Astrophysics. 390 (1): 299–306. arXiv:astro-ph/0205128v2. Bibcode:2002A&A...390..299B. doi:10.1051/0004-6361:20020627. S2CID 6002327.
  6. ^ Gabel, J.R.; Bruhweiler, F.C. (8 January 1998). "[51.09] Model of an expanding supershell structure in the LISM". American Astronomical Society. Archived from the original on 15 March 2014. Retrieved 14 March 2014.
  7. ^ Maíz-Apellániz, Jesús (1 October 2001). "The Origin of the Local Bubble". The Astrophysical Journal. 560 (1): L83–L86. arXiv:astro-ph/0108472. Bibcode:2001ApJ...560L..83M. doi:10.1086/324016. ISSN 0004-637X.
  8. ^ Fuchs, B.; Breitschwerdt, D.; de Avillez, M. A.; Dettbarn, C.; Flynn, C. (1 December 2006). "The search for the origin of the Local Bubble redivivus". Monthly Notices of the Royal Astronomical Society. 373 (3): 993–1003. arXiv:astro-ph/0609227. Bibcode:2006MNRAS.373..993F. doi:10.1111/j.1365-2966.2006.11044.x. hdl:10174/5608. ISSN 0035-8711.