Anders Celsius (November 27, 1701 – April 25, 1744) was a Swedish astronomer. Celsius was born in Uppsala in Sweden. He was professor of astronomy at Uppsala University from 1730 to 1744, but traveled from 1732 to 1735 visiting notable observatories in Germany, Italy and France. At Nuremberg in 1733 he published a collection of 316 observations of the aurora borealis made by himself and others over the period 1716-1732. In Paris he advocated the measurement of an arc of the meridian in Lapland, and in 1736 took part in the expedition organized for that purpose by the French Academy of Sciences, led by the French mathematician Pierre Louis Maupertuis. Celsius founded the Uppsala Astronomical Observatory in 1741, and in 1742 he proposed the Celsius temperature scale in a paper to the Royal Swedish Academy of Sciences.