Bibcode
Balthasar, H.; Vazquez, M.; Woehl, H.
Bibliographical reference
Astronomy and Astrophysics (ISSN 0004-6361), vol. 155, no. 1, Jan. 1986, p. 87-98. Research supported by the Consejo Superior de Investigaciones Cientificas.
Advertised on:
1
1986
Citations
227
Refereed citations
212
Description
An effort is made to determine the differential rotation of the sun on
the basis of the complete sample (1874-1976) of the Greenwich
Photoheliographic Results. In order to improve the representation of
differential rotation, a modified fit formula whose constant lies at 15
deg latitude (where sunspots nearly always occur) is introduced.
Rotation is noted to strongly depend on sunspot type, with C-groups
exhibiting high velocities and H- and J-spots the lowest ones. The new
fit formula indicates that the highest velocity is found around the
minima; at the beginning of an activity maximum, there is a secondary
velocity maximum. The lowest velocities lie between the activity maximum
and minimum. The braking of recurrent sunspots is confirmed.