sentence: orbit solutions several orbits have been calculated , including w.c. jacob ( 1850 ) , bernhard dawson ( 1919 ) , w.j. luyten & e.g. ebbinghausen ( 1934 ) , and j.g. gore ( 1956 ) the most recent solution being produced by the dutch astronomer gale bruno van albada ( 1957 ) , while he was acting as the director of the bosscha observatory in java , indonesia .