Black Hole Cygnus X-1

[mattie]

This is a good example of how scientific knowledge works as 30 years ago Stephen Hawking speculated that there wasn’t a black hole in Cygnus X-1. Given an additional 3 decades of observation w/ increasingly better instruments, scientists now have enough additional information to be confident this is a black hole.

NASA article about this black hole.
http://www.nasa.gov/mission_pages/chandra/news/cygnusx1.html

http://www.nasa.gov/images/content/604629main_cygnusx1_226.jpg
Illustration of Cygnus X-1.