1. What is Angular Resolution?

Angular resolution describes the ability of a telescope to distinguish small details of distant objects. For the Hubble Space Telescope, this determines how close two point sources can be while still being distinguishable.

2. How Does the Calculator Work?

The calculator uses the Rayleigh criterion formula:

Where:

• \( \theta \) — Angular resolution (in radians, converted to arcseconds)
• \( \lambda \) — Wavelength of observed light (in meters)
• \( D \) — Diameter of telescope's primary mirror (in meters)
• 1.22 — Constant derived from the Rayleigh criterion

Explanation: The formula shows that resolution improves with larger apertures and shorter wavelengths.

3. Importance of Angular Resolution

Details: Higher angular resolution allows astronomers to see finer details in astronomical objects, distinguish close binary stars, and resolve smaller structures in galaxies and nebulae.

4. Using the Calculator

Tips: Enter wavelength in meters (e.g., 550 nm = 5.5e-7 m) and telescope diameter in meters (Hubble's = 2.4 m). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is Hubble's typical resolution?
A: For visible light (500 nm), Hubble's resolution is about 0.05 arcseconds with its 2.4-meter mirror.

Q2: Why does wavelength affect resolution?
A: Longer wavelengths diffract more, making it harder to resolve small details. This is why radio telescopes need much larger dishes than optical telescopes.

Q3: Can resolution be better than this formula predicts?
A: Adaptive optics and interferometry can sometimes achieve better resolution, but this formula describes the theoretical limit for a perfect optical system.

Q4: How does atmospheric seeing affect ground-based telescopes?
A: Atmospheric turbulence typically limits ground-based optical telescopes to about 0.5-1 arcsecond resolution, regardless of their aperture size.

Q5: What's the resolution of the James Webb Space Telescope?
A: JWST's 6.5-meter mirror gives it about 0.02 arcsecond resolution at 2 μm wavelength.