Sigurd Einbu (1866-1946) was a self-educated astronomer from a mountainous area in Central Norway. He built his own observatory on his farm at Dombås - in North Gudbrandsdalen where he observed variable stars with a 12.5 cm refractor. He became in 1923 a member of the Astronomical Union and produced in total 14 scientific publications. He was also a popular lecturer, traveling on lecture tours when the moon was too bright to observe, and he wrote popular astronomy books and thousands of astronomical notices to newspapers. In addition he was responsible for magnetic and auroral observations at Dombås, in addition to weather observations and map making for the Norwegian Almanac. He had a large correspondence both national and international, and did not throw away letters. Recently boxes with 4000 letters have been found, and from these we have learned about his life and activities.
In the evening of March 12, 1912 Sigurd Einbu discovered a new star in the constellation Gemini. The star was of magnitude 4, and he was the first to report it to the Central Bureau for Astronomical Telegrams in Kiel. This was a big event in astronomy, where the newly built large telescopes equipped with spectrographs tried to capture this unique event. The sudden flaring of light also inspired Albert Einstein who visited Potsdam Observatory in April 1912. In a newly discovered notebook from this visit the equations for light amplification with a gravitational lens for the first time is calculated. It took 52 years to find an explanation of a Nova and 15 years later the first gravitational lensed object was found.
To celebrate Sigurd Einbu and his Nova discovery - 3 exiting astronomical days will take place in Nord Gudbrandsdal March 11, 12, 13, 2012. A book about Einbu and his work will be launched on March 12 at Dombås. Authors are Gunnar Bentdal, Asgeir Brekke, Øyvind Nordli, Jan-Erik Solheim and Bjørn Ragnvald Pettersen and the title is En himmelrommets fyrvokter, Sigurd Einbu.