National Astronomical Observatory of Japan

Three Pupils Following the Sun, the Solar Flare Telescope


Three Pupils Following the Sun, the Solar Flare Telescope

The action in astronomy doesn’t necessarily all happen at night. One very clear autumn day, the Solar Flare Telescope located in NAOJ Mitaka Campus follows the dazzling bright Sun in the blue sky. The Solar Flare Telescope is a dedicated use telescope which can simultaneously observe the state of activity and magnetic field strength across the entire solar disk in visible and infrared wavelengths. Observations continue every day with the aim of elucidating the mechanisms of long period changes in solar activity. This is currently the primary observational instrument of the NAOJ Solar Observatory.

A Comprehensive Observational Instrument for Solar Flares

Solar flares are explosive phenomena occurring in the corona, high temperature gas extending around the exterior of the Sun. The Sun has strong magnetic fields. The black spots (sunspots) appearing on the Sun’s surface show active regions where magnetic field lines are bunched together. It is thought that when the magnetic energy contained in these active regions is released, a flare occurs heating the outer corona gas. During solar maximum, which repeats roughly every 11 years, many sunspots occur and the number of flares which occur increases. But when we look at long term activity, there are times when this cycle is disrupted. To understand the mechanisms for these kinds of changes in the Sun, it is necessary to continue acquiring systematic solar activity data spanning long periods.

Two each of 15 cm and 20 cm aperture telescopes are installed in the Solar Flare Telescope located on the north-west side of Mitaka Campus. Each mounts a different instrument enabling comprehensive observations of solar activity. Currently, 3 instruments measure sunspots, flare activity, and magnetic field distribution.

Text by : Seiichiro Naito (Public Relations Center, NAOJ)
Translation by: Ramsey Lundock (Public Relations Center, NAOJ)