The Solar Observatory of NAOJ

The National Astronomical Observatory of Japan has a history of about 100 years of regular synoptic solar observations. It started with Ca K spectroheliographic and white-light imaging observations, and shortly afterward, sunspot count was started. Current imaging observations are being carried out in the Ha line, the Ca K line, the green continuum, and the G-band. In addition, the NAOJ has a history of more than 30 years of magnetic field measurements, and now we are conducting full-Sun spectropolarimetry observations in the wavelengths of He I 10830/Si I 10827 and Fe I 15648. These observational results contribute not only to the monitoring of solar active phenomena from the viewpoint of the space weather, but also to the study of the long-term variability of the solar activity, thanks to the long history. Most of historical photographic (plates and films) and hand-drawn data have been digitized and are now open at our web site as well as recently obtained data. Here we introduce our data to promote the collaboration in the long-term solar activity study. Our data are open at our website: visit http://solarwww.mtk.nao.ac.jp/en/solarobs.html, and go to the database page.