Motions of photospheric features in a sunspot moat

Sobotka, M.; Bonet, J. A.; Márquez, I.; Muller R.; Roudier, Th.
Bibliographical reference

Hvar Observatory Bulletin, vol. 28, no. 1, p. 27-36.

Advertised on:
2004
Number of authors
5
IAC number of authors
2
Citations
0
Refereed citations
0
Description
Two time series, taken simultaneously in the G-band and the blue continuum, corrected for instrumental and atmospheric degradation 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. Centres of diverging horizontal motions, identified with families of granules formed by recurrently splitting granules, move away from the sunspot. Most of GBPs show radially oriented motions in the same direction, with velocities comparable to those of adjacent granules. However, 7 % of GBPs move faster (>1.4 km s-1) than the neighbouring granules.