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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 H-alpha 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 monitoring the solar active
phenomena from the viewpoint of the space weather, but also to studying 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.
In the meeting, we will introduce our data to promote the collaboration in the
long-term solar activity study. |
