Cygnus X-1 and LMC X-3 are binary systems with one component not visible.What must the unseen component masses be for astronomers to be certain that these systems contain a black hole?
A)less than 0.4 solar masses
B)between 0.4 and 1.4 solar masses
C)less than 5 solar masses
D)more than 5 solar masses

Question

Quizplus · Accepted Answer

For astronomers to be certain that these systems contain a black hole, the unseen component masses need to be more than 5 solar masses. This is because the upper limit for the mass of a neutron star is around 3 solar masses, so any unseen component with a mass greater than this would have to be a black hole. Choice A is incorrect because the mass of a white dwarf, which is another possible candidate for the unseen component, is less than 1.4 solar masses. Choice B is incorrect because this range includes both neutron stars and white dwarfs as possible candidates. Choice C is incorrect because the upper limit for the mass of a neutron star is around 3 solar masses, and there are observed neutron stars with masses greater than 5 solar masses.

Cygnus X-1 and LMC X-3 Are Binary Systems with One