Stars much more massive than our Sun can eventually form black holes at the end of their life cycle.
Describe how a black hole is formed from such a massive star.
The high-mass X-ray binary system Cygnus X-1 contains one of the first widely accepted stellar-mass black holes. The system is approximately 610061006100 light-years from the Earth.
Explain what is meant by the unit light-year.
Calculate the approximate distance from Cygnus X-1 to the Earth in kilometres km\text{km}km. Give your answer in standard form to 2 significant figures.
104 exam-style questions on CIE IGCSE Physics 6.2 Stars and the Universe, covering 6.2.1 The Sun as a star, 6.2.2a Galaxies and astronomical distances, 6.2.2b The life cycle of a star, 6.2.3a Galaxies and the scale of the Universe, 6.2.3b Redshift, 6.2.3c The Big Bang Theory and cosmic microwave background radiation, and 6.2.3d The Hubble constant and the age of the Universe. Each one has a worked solution and a mark scheme showing where the marks go.