Which observational error was reduced when 10th-century Islamic astronomers introduced the alidade sight on astrolabes?

💡 Explanation

When astronomers used the alidade with pinhole sights, instrument misalignment error was reduced because the design allowed for more accurate alignment of the instrument with the target star, minimizing angular errors. Therefore, instrument misalignment improved, rather than parallax, aberration or limb darkening errors, which depend on other atmospheric and optical properties.

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