Ergosphaera
Ergosphaera (ex Graeco ergon 'opus' + sphaera 'globus') in theoria relativitatis generalis est regio extra foramen nigrum revolvens, quae sic nominata est quia energia et massa ex foramine nigro hac in regione secundum doctrinam evellere possunt.

Nexus externi 
 http://nrumiano.free.fr/Estars/bh_thermo.html
 http://adsabs.harvard.edu/abs/2002astro.ph..3421W
 https://web.archive.org/web/20111017221919/http://www.daviddarling.info/encyclopedia/E/ergosphere.html
 http://astro.cornell.edu/academics/courses/astro201/ergosphere.htm

Astronomia
Foramina nigra