On the Magneto-convective origin of Light Bridges observed with Hinode

Sreejith, P., Nagaraju, K., Sankarasubramanian, K., Rangarajan, K. E.

Ground based observations are limited by the atmospheric seeing conditions. This scenario especially limits the observations of evolutions of small-scale features on the Sun. Recent emergence of high spatial resolution observations from space with Hinode can provide data to study the time evolutions uninterruptedly. We have used one such observation to study the time sequence evolution of a light bridge in a sunspot. The Spectro-polarimetric data collected using SOT on Hinode, is used to create a complete vector field map of the light bridge. The G-band images observed provide us with the data to understand the feature evolution at a very high spatial resolution.

The physical origin of small scale structures in sunspots like umbral dots and light bridges are still debated between magneto-convective origin and field free convective origin. Data obtained until now with ground based observations does favour both the models equally. In this paper we
present the time evolution analysis of a light bridge observed from space and show it convincingly that these are indeed field free convection. We also present the implications of these results on the sunspot structure as a whole.