Final answer:
John and Jake can use spectroscopy to determine the elements composing the stars. By analyzing the spectral lines, they can identify the presence of different elements. Other observations can help ascertain if the stars are binary and if their color is affected by interstellar dust.
Step-by-step explanation:
John and Jake are interested in determining the composition of two stars they are observing in their laboratory. The best tool for this job is spectroscopy, which is a technique used to analyze light. When a star's light is passed through a prism or a diffraction grating, it is spread out to form a spectrum. The spectrum contains distinct lines that can signal the presence of specific elements in the star's atmosphere because each element emits or absorbs light at specific wavelengths. By comparing these spectral lines with those known from laboratories on Earth, astronomers can decode the light we receive from the stars to learn about their chemical composition. In addition to composition, measurements such as luminosity, temperature, and changes in a star's spectrum can also help to determine if the stars are binary (orbiting each other) or if they are just coincidentally aligned. To differentiate between stars that are truly red and those that appear red due to interstellar dust, astronomers may observe other factors such as the stars' apparent brightness, magnitude, and changes in their light over time.