Calculateur de Résolution de Télescope

Calculez la résolution angulaire de votre télescope.

mm

Dawes Limit

0.580 arcsec

Rayleigh Limit0.690 arcsec

Dawes Limit vs Aperture Diameter

Formule

Telescope Angular Resolution

Dawes Limit (empirical, for equal-brightness stars)

theta = 116 / D arcseconds (D in mm)

Rayleigh Criterion (diffraction-limited at 550 nm)

theta = 138 / D arcseconds

Smaller is better. A 200 mm telescope resolves about 0.58 arcsec. Atmospheric seeing typically limits ground-based resolution to about 1-2 arcsec.

Exemple Résolu

A 200 mm (8-inch) telescope.

  1. 01Dawes: 116 / 200 = 0.58 arcsec
  2. 02Rayleigh: 138 / 200 = 0.69 arcsec
  3. 03This can split double stars separated by 0.6 arcsec on a steady night.

Questions Fréquentes

What limits resolution in practice?

Atmospheric seeing (turbulence) typically limits ground resolution to 1-2 arcsec, regardless of telescope size. Adaptive optics or space telescopes overcome this.

What is the Hubble Space Telescope's resolution?

About 0.05 arcsec, thanks to its 2.4 m aperture and no atmospheric blurring.

Does magnification improve resolution?

No. Resolution is set by aperture. Magnification just makes the resolved detail easier to see, up to a point.

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