The Resolving Power of a Telescope calculator computes the angular distance between two stars on the limit of visibility for a telescope.
INSTRUCTIONS: Choose units and enter the following:
Resolving Power (α): The calculator returns the Resolving Power in arc seconds.
The resolving power of a telescope is the angular distance between two stars that are just barely visible through the telescope as separate images. The resolving power α in arc seconds of a telescope with diameter D in meters that is collecting light of wavelength λ in nanometers equals is given by this formula. The formula for the resolving power of a telescope is:
`α = 2.06 x 10^5 ( λ / D )`
where: