Final answer:
Binary stars are pivotal for astronomers in measuring stellar masses and understanding stellar dynamics, including the formation of black holes. These systems, especially when massive, help in detecting gravitation waves, enhancing our cosmological knowledge.
Step-by-step explanation:
Binary stars are crucial to astronomers because they provide valuable data on stellar masses and the fundamentals of stellar evolution. Binary stars orbit each other and are bound by gravity, allowing scientists to calculate their masses by analyzing their orbits, similar to how the Sun's mass is measured through the movement of planets. This critical method is the mass-luminosity relation. Moreover, binary star systems are significant in the search for gravitation waves using instruments like LIGO because those systems, especially when they include massive stars or black holes, can generate detectable ripples in spacetime.
Binary stars are not necessarily important because they all have planets, as that statement is inaccurate. Their importance lies in their mass and their interactions, which can lead to phenomena like black holes or allow for the calculation of stellar masses, which further our understanding of the universe. Whether a binary star system is a good candidate for forming a black hole depends on the mass of the stars and the dynamics of their orbit, which are important for the eventual fate of the binary system and its ability to warp spacetime.