Nagoya University researchers analyse solar observation records in the collection of Kawaguchi City Science Museum

A research group led by Designated Assistant Professor Hisashi Hayakawa of the Tokai National University Institute, Graduate School of Advanced Studies, Nagoya University/Institute for Space-Earth Environmental Research, Kawaguchi City Science Museum (Saitama Prefecture), National Astronomical Observatory of Japan, and Royal Observatory of Belgium (Kingdom of Belgium) and others, we analyzed the past 40 years of solar observation records kept at the Kawaguchi City Science Museum. As a result, it was found that (1) the sunspot relative numbers and the World Data Center for Long-term Solar Observations (SILSO) at the Royal Observatory of Belgium have a larger amount
of solar observation records, and (2) all observations are , the observation record of the same person at the Kawaguchi Science Museum (which is a rare case in the world), and (3) the stability is one of the best in the world compared to the data of long-term sunspot observers around the world. clarified . Sunspot relative numbers Note 1)
based on sunspot observations are extremely valuable data that can provide information over the past several centuries in reconstructing long-term changes in solar activity on a direct observation basis. In recent research, reconstruction of solar activity has problems such as calibration of individual observations, and reconstruction results do not always match. What is important to overcome this problem is highly homogeneous observation data from individual observers. Due to its world-class stability, the museum’s observational record may greatly contribute to ongoing efforts to recalibrate solar activity over the past several centuries . In addition, the original sunspot sketch record in the museum is expected to contribute not only to the long-term variation of solar activity but also to the understanding of short-term space weather phenomena . In addition, this sunspot sketch record has been released on the website of the Kawaguchi City Science Museum.