Authors: T.E. Berger, B.W. Lites, R.A. Shine, T.D. Tarbell, A.M. Title
Affiliation: Lockheed Martin, Solar and Astrophysics Laboratory
The Solar Optical Telescope (SOT)/Focal Plan Package (FPP) instrument will be launched aboard the Japanese Solar-B satellite in late summer 2006. The SOT is a 0.5-meter Gregorian telescope featuring an active tip-tilt image stabilizing tertiary mirror and constantly rotating polarization modulator unit. The diffraction-limited resolution of the SOT is 0.2 arcsec at 393 nm and 0.3 arcsec at 630 nm. The FPP consists of an Fe I 630.2 nm scanning spectropolarimeter, a narrow-band tunable Lyot filter capable of 10 pm spectral resolution in key optical lines from Mg Ib 517.3 nm to H-alpha at 656.3 nm, and a wide-band interference filter system including Ca II H-line, G-band, and RGB continuum filters. Each instrument has a field-of-view of several arcminutes and their combination will provide powerful high-resolution diagnostics of the solar photosphere and chromosphere. Vector magnetic field maps with 1e-03 or better precision and 0.3 arcsec resolution will be combined with high-cadence 0.2-0.3 arcsec resolution filtergram movies to study active region emergence, sunspot physics, small-scale magnetic flux dynamics, sources of photospheric and chromospheric irradiance, waves and flows in the solar atmosphere, as well as impulsive events such as flares, prominence destabilization, and CMEs. Combined with the X-ray Telescope (XRT) and the Extreme-ultraviolet Imaging Spectrograph (EIS) on the Solar-B satellite, the SOT/FPP instrument will answer fundamental questions about the nature of solar magnetic activity, its origins, dynamic evolution, and connections to the geospace environment. SOT/FPP can be viewed as the high-resolution "optical microscope" for the LWS/SDO mission, providing precision vector magnetic field, photospheric flowfield, and chromospheric images over the course of Solar Cycle 24.