The Airy Disc and Bright Rings Surrounding a Star in a Telescope

What are the radii of the first, second, and third bright rings surrounding the Airy disc in the diffraction pattern formed by a star observed through a telescope at the Lick Observatory?

Radii of the Bright Rings

The Lick Observatory is home to one of the largest refracting telescopes, with an aperture diameter of 36 inches and a focal length of 56 feet. The diffraction pattern formed by a star on the focal plane of the objective results in the formation of an Airy disc surrounded by bright rings. The radii of these rings can be determined using the formula for the angular radius of the nth ring, which is given by θ = 1.22(λ/D), where λ is the wavelength of light and D is the aperture diameter. Given that the aperture diameter is 36 inches (approximately 0.9144 meters) and assuming a typical wavelength of visible light around 550 nm, we can calculate the angular radii of the first, second, and third bright rings. However, without specific values for the wavelength of light and the desired order of the bright rings, precise calculations cannot be provided. The radii of the rings surrounding the Airy disc are influenced by these parameters. Make a sketch of the diffraction pattern and determine how much light is contained in the central part of the Airy disc.

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