Motions of IsolatedG‐Band Bright Points in the Solar Photosphere

Magnetic elements on the quiet sun are buffeted by convective flows thatcause lateral motions on timescales of minutes. The magnetic elements can beobserved as bright points (BPs) in the G band at 4305 {\AA}. We presentobservations of BPs based on a long sequence of G-band images recorded with theDutch Open Telescope (DOT) and post-processed using speckle masking techniques. From these images we measured the proper motions of isolated BPs and derivedthe auto-correlation function of their velocity relative to the solargranulation pattern. The accuracy of BP position measurements is estimated tobe less than 23 km on the Sun. The rms velocity of BPs (corrected formeasurement errors) is about 0.89 km s$^{-1}$, and the correlation time of BPmotions is about 60 s. This rms velocity is about 3 times the velocity measuredusing cork tracking, almost certainly due to the fact that isolated BPs movemore rapidly than clusters of BPs. We also searched for evidence of vorticityin the motions of G band BPs.Comment: 9 Pages, 6 figures, Accepted for publication in Astrophysical Journal, Part