Andrew Ainslie Common (1841-1903), British astronomer. Common used photographic techniques to make observations, and his photograph of the Orion Nebula, taken in 1883, won him the Gold Medal of the Royal Astronomical Society. He served as the president of the society in 1895-6. He conducted his work at his private observatory in London, also building several high-quality telescopes, including a 60 inch (1.52 metres) reflector.