Bibcode
Bonet, J. A.; Márquez, I.; Muller, R.; Sobotka, M.; Roudier, Th.
Bibliographical reference
Astronomy and Astrophysics, v.430, p.1089-1097 (2005)
Advertised on:
2
2005
Journal
Citations
17
Refereed citations
15
Description
Two time series, taken simultaneously in the G-band and in white-light,
and corrected for telescope aberrations and turbulence perturbations
using the method of phase diversity, are employed to study the motions
of granules and G-band bright points (GBPs) in the moat of an old
regular sunspot. Local correlation tracking and feature tracking have
been utilized for this purpose. A large-scale radial outflow with a mean
velocity of 0.51 km s-1 has been measured in the sunspot
moat. Centres of diverging horizontal motions, identified with families
of granules formed by repeatedly splitting granules, move away from the
sunspot. Most of the GBPs in the moat also move outwards through
radially orientated ``channels'' (confined between the borders of
adjacent families) with velocities comparable to those of the adjacent
granules. However, 6% of the GBPs move faster (>1.4 km
s-1) than the neighbouring granules. GBPs in the moat are not
regularly distributed but they are less frequent on its solar centre
side.