Olof Hiorter in 1747. Olof Hiorter Olof Petrus (or Peter) Hiorter (or Hjorter) (1696–1750) was a Swedish astronomer. After studying in the Netherlands, he was appointed lecturer at the University of Uppsala in 1732 to fill the vacant position of Anders Celsius then on his grand tour of European observatories. From 1737 onwards, he studied together with Celsius the aurora phenomenon and a number of astronomy subjects (solar eclipse, comet like the one of 1744, latitude measurements). Pehr Wilhelm Wargentin was his pupil. Hiorter was elected a member of the Royal Swedish Academy of Sciences in 1745 and appointed "Observator Regius" -
Christian Mayer (astronomer) able to continue his astronomical observations and studies. He applied for and was granted in December 1765 a Fellowship of the Royal Society. He is most noted for pioneering the study of binary stars, although his equipment was ill-suitable for distinguishing between true binaries and coincident star alignments. In 1777-78 he compiled a catalog of 80 double stars, which he published in 1781. During his lifetime he became a member of numerous learned societies. He died in Heidelberg. Christian Mayer (astronomer) Christian Mayer (August 20, 1719 – April 16, 1783) was a Czech-German Catholic priest, astronomer and teacher. He was