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Summary
DescriptionCygnus X-1.png
English: An artists illustration of material being gravitationally sucked off a blue supergiant variable star designated HDE 226868 onto a black hole Cygnus X-1
This file is in the public domain because it was created by NASA and ESA. NASA Hubble material (and ESA Hubble material prior to 2009) is copyright-free and may be freely used as in the public domain without fee, on the condition that only NASA, STScI, and/or ESA is credited as the source of the material. This license does not apply if ESA material created after 2008 or source material from other organizations is in use.