I saw a statement being made in a video, but it didn't explain why. It originally said, "stars orbiting each other does not create gravitational waves, binary system of two massive stars or black hole does." This baffles me because a planet orbiting a star is essentially also a binary system.
1 Answer
The statement is wrong, though sort of true. Gravitational waves are exceedingly hard to create and significant energy is radiated as gravitational waves only for massive stars rotating rapidly at a short distance. In principle the Earth-Moon system radiates gravitational waves, but at such a ridiculously low intensity that it's fair to say it doesn't radiate at all.
For more on this have a look at my answer to Is it possible to produce gravitational waves artificially? where I discuss the equation for the energy radiated as gravitational waves.