During this observation, the SOT observes a sunspot continuously for at least 12 hours with a constant cadence (about 1 min). Taking continuous enon-magneticf photospheric Dopplergrams of a sunspot is important for sunspot diagnostic by local helioseismology; since the Dopplergrams are not contaminated by magnetic fields, to investigate subsurface structure of the region where magnetic flux is strong, such as sunspots, it is useful. According to our previous works using the Dopplergrams, we need a continuous observation at least 12 hours to achieve sufficient S/N ratio. Coordination with MDI will be attempted. |
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