A deep-space monitoring station in the Atacama Desert operates two co-aligned optical telescopes, Telescope X and Telescope Y, mounted together to observe the same region of the sky. Table 1 lists key specifications for these instruments.
| Telescope | Design | Objective diameter / mm\text{mm}mm |
|---|---|---|
| X | Refractor | 120 |
| Y | Reflector | 720 |
Both telescopes are used to observe a faint, distant nebula. State which telescope produces the brighter image and support your answer with an appropriate calculation.
The theoretical limit for distinguishing close stellar objects is determined by the Rayleigh criterion. Explain what is meant by the Rayleigh criterion.
Deduce which of the two telescopes in Table 1 is better suited to resolve the individual components of a tightly-bound binary star system.
