This artist's illustration depicts the principal elements of the Cygnus X-1
system. Cygnus X-1, the first black hole to be discovered, is a
so-called stellar-mass black hole, a class of black holes that comes
from the collapse of a massive star. The black hole pulls material
from a massive, blue companion star toward it. This material forms a
disk (shown in red and orange) that rotates around the black hole
before falling into it or being redirected away from the black hole in
the form of powerful jets (Credit: Chandra press office).
Our results on the distance to the Cygnus X-1 system and on the mass
and spin of its black hole are available in this
press-release and in this feature article, which
appeared in Physics World magazine.
To view our sequence of three journal papers on Cygnus X-1,
click distance, mass and spin.