Unraveling the Mystery: Is It a Black Hole?

Which of the following properties suggests that the companion is definitely a black hole?

A.) the mystery companion has a mass of over 3 solar masses

B.) the mystery companion has an X-ray emitting accretion disk

C.) the mystery companion gives off periodic X-ray bursts

D.) the mystery companion has a mass of over 1.4 solar masses

Final Answer:

The property that definitely suggests the companion to an evolved star is a black hole is its mass being over 3 solar masses.

When studying a mystery companion to an evolved star, particularly addressing mass transfer, there are certain traits that indicate the companion might be a black hole. These characteristics can be used to distinguish between neutron stars, white dwarfs, and black holes.

Among the properties listed, the fact that the mystery companion has a mass of over 3 solar masses (Option A) strongly suggests the presence of a black hole. According to the Oppenheimer-Volkoff limit, which is a theoretical upper limit to the mass of stars before they collapse into a neutron star or a black hole, anything with a mass more than about 3 solar masses cannot be a neutron star and would most likely be a black hole.

The presence of an X-ray emitting accretion disk (Option B) and periodic X-ray bursts (Option C) are traits that can be exhibited by neutron stars, black holes, and other types of compact objects, and thus do not explicitly suggest that the companion is a black hole. Similarly, possessing mass over 1.4 solar masses (Option D) indicates the companion object is a neutron star or a black hole but does not specifically single out the entity as a black hole.