Anders Celsius magnitude (a measure of brightness) of certain stars. This was the first attempt to measure the intensity of starlight with a tool other than the human eye. He made observations of eclipses and various astronomical objects and published catalogues of carefully determined magnitudes for some 300 stars using his own photometric system (mean error=0.4 mag). Celsius was the first to perform and publish careful experiments aiming at the definition of an international temperature scale on scientific grounds. In his Swedish paper "Observations of two persistent degrees on a thermometer" he reports on experiments to check that the freezing point is
David Kennedy (astronomer) David Kennedy (astronomer) David Kennedy (27 April 1864 – 10 March 1936) was born at Lyttelton, New Zealand, the son of an Irish mother and a Scottish father who came to New Zealand from Melbourne in 1863. He became the first New Zealand born priest of the Society of Mary (Marists), a noted astronomer and educator. As a boy he showed a keen interest in both theology and science. Because of his undoubted intelligence and promise he was sent to study at the Marist college at Dundalk, Ireland in 1878. In 1884 he entered the Marist novitiate at Paignton, England,