Named in memory of the Swedish astronomer Anders Celsius (1701–1744), renowned for devising the thermometric scale. A participant in the French expedition to Lapland to measure the curvature of the Earth, he was also the first astronomer to try to determine stellar magnitudes by photometric methods. The year 1990 marks the 250th anniversary of his establishment of the Uppsala Observatory, the original building of which is still preserved in the center of Uppsala. The event has been celebrated at the Nordic-Baltic Astronomy Meeting held in Uppsala during 1990 June 17–21. (M 16044) _ _.