Resolving and collecting power of telescopes (AQA A-Level Physics): Flashcards

Ability to distinguish between closely spaced objects

$\theta \approx \frac{\lambda}{D}$

Diameter of objective (lens or mirror)

Wavelength of electromagnetic radiation

Angular separation $\geq \frac{\lambda}{D}$

Smaller $\theta$, better resolution (finer details)

$D^2$ (square of objective diameter)

Quadruples it (increases by factor of 4)

1/3600 of a degree

Diffraction pattern: bright central disc + concentric rings