  The magnetic and transition magnetic moments of the ground-state baryons are
computed in heavy baryon chiral perturbation theory in the large-$N_c$ limit,
where N_c is the number of colors. SU(3) symmetry breaking is systematically
studied twofold: On the one hand, one-loop nonanalytic corrections of orders
m_q^{1/2} and m_q ln m_q are included, with contributions of baryon
intermediate states from both flavor octet and flavor decuplet multiplets,
assuming degeneracy between baryon states within a given flavor multiplet but
nondegeneracy between baryons of different multiplets. On the other hand,
perturbative SU(3) symmetry breaking is also analyzed by including all relevant
leading-order operators that explicitly break SU(3) at linear order. The
resultant expressions are compared with the available experimental data and
with other determinations in the context of conventional heavy baryon chiral
perturbation theory for three flavors of light quarks and at the physical value
$N_c=3$. The agreement reached is quite impressive.
