Flare Patrol Telescope
H-alpha flare patrol observations at Mitaka were performed visually by a spectrohelioscope from 1948 to 1965. Then in 1957 in the IGY period a monochromatic heliograph (made in France) was installed. Photographic observations had been continued up to 1992, when a new system based on a video camera and a computer was introduced.
The automated flare-patrol system was made of an objective lens, which had an aparture of D = 40 mm and focal length of f = 600 mm, a birefringent filter made by Halle, Germany, and a XC-77 CCD camera (768 x 493 pixels). Digitized H-alpha images of the solar disk were obtained every one minute. If a flare was detected, a one-second cadence data recording was started automatically. The system was initially put on top of the monochromatic heliograph and installed on the new sunspot telescope at a later time to observe H-alpha flares until 2003. In 2008, its objective was changed to an achromatic lens, which had an aparture of D = 50 mm and focal length of f = 700 mm, with a 0.6 times focal reducer and the camera was replaced with a TAKEX FC800 CCD camera (1077 x 788 pixels, 10 bit A/D). The latest system of flare-patrol telescope, which was taken an image with a cadence of 10 seconds, was operated between 2008 and 2019.
