Friedrich Georg Wilhelm von Struve ( April 15 , 1793 â `` November 23 , 1864 ( Julian calendar : November 11 ) ) was a German-born Russian astronomer . Friedrich Georg Wilhelm von Struve ( April 15 , 1793 â `` November 23 , 1864 ( Julian calendar : November 11 ) ) was a Russian astronomer of Baltic-German origin from a famous dynasty of astronomers .